Children's Use of Frames of Reference inConununieation of Spatial Location

Lincoln G. Craton, James Elicker, Jodie M. Plumert, andHerbert L. Pick, Jr.University of Minnesota

GRATON, LINOJLN G.; ELICKER, JAMES; PLUMERT, JODIE M.; and PICK, HERBERT L., JR. Children'sUse of Frames of Reference in Communication of'Spatial Location. GHILD DEVELOPMENT, 1990, 61,1528—1543. The frames of reference used by 4-, 6-, and 8-year-old children were studied in a spatialdirection-giving task. Ghildren were asked to specify verbally the location of a toy hidden under oneof several identical cups. The child and listener sat facing each other at opposite ends of a room thathad distinctive or nondistinctive landmarks proximal and distal to the hiding location. Locationneeded to be specified with respect to either the left-right dimension, the front-back dimension, orboth. The results indicated that (1) although children's overall performance improved with age,communication about the left-right dimension was particularly difficult for 4-year-oId children andshowed a higher rate of improvement with age than communication about the front-back dimension;and (2) the frames of reference that children incorporated into their directions changed with age anddiffered for directions about the front-back and left-right dimensions. Both 4- and 6-year-old childrenused person references (themselves or the listener) to specify front-hack relations, but only the 6-year-olds were able to compensate for their apparent difficulty in using the terms left and right byusing landmarks to specify the left-right dimension. Eight-year-olds used a combination of personand landmark references in directions about both dimensions. Discrepancies between the frames ofreference children used to communicate spatial location and those typically used in other spatialcognition tasks are discussed in terms of developmental and task constraints.

Civing directions to someone about how Krauss, & Higgins, 1975; Sonnenschein,to get somewhere or how to find something is 1988).a common everyday task. Yet it is interest-ingly complex. Communicating information Spatial direction-giving is a form of ref-about spatial location is challenging for chil- erential communication in which the goal isdren because two different types of informa- to enable the listener to distinguish a targettion, spatial and verbal, must be coordinated, location or route (the referent) from all possi-This activity requires at least: (1) accessing ble alternatives (nonreferents). Few empiricalone's spatial knowledge about the target loca- studies of the development of referential com-tion, (2) selecting information from the envi- munication skills have been explicitly con-ronment that will distinguish the target loca- cerned with spatial reference. Instead, mosttion from other locations, and (3) linguistically developmental referential communicationencoding that infonnation in a message that studies have been concerned with distin-takes into account the knowledge and capac- guishing a target stimulus (typically, a word ority of the listener. These processes have been graphic shape) from a set of similar items,isolated and studied in various forms by re- This work has been strongly infiuenced bysearchers interested in spatial cognition (e.g., Piaget's (1929) contention that young childrenPiaget & Inhelder, 1967; Piaget, Inhelder, & are egocentric (i.e., unable to accommodateSzeminska, 1960; for a recent review, see Co- the perspective of a listener in a communi-hen, 1985), psycholinguistics (e.g., Johnston, cation situation). On both empirical and theo-1981; Klein, 1982; Linde & Labov, 1975), and retical grounds, reviewers of tbis literaturereferential communication (e.g., Glucksberg, conclude that the attempt to relate develop-

The order of authorship on this paper is arbitrary and reflects equal contribution on the part ofeach author. This research was supported by NIGHD grant HD-07151, through the Genter forResearch in Leaming, Perception, and Gognition. The authors wish to thank the children andteachers of the University of Minnesota Shirley G. Moore Nursery School, St. Anthony ParkElementary School, and Gorpus Ghristi School for their enthusiastic cooperation; Paule Graton forher help in transcribing the data; and Janet Malz for helping code and analyze the data. Requests forreprints should be sent to Herbert L. Pick, Jr., University of Minnesota, Institute of Ghild Develop-ment, 51 East River Road, Minneapolis, MN 55455.

[Child Development, 1990, 61, 1528-1543. © 1990 by the Society for Research in Child Development, Inc.All rights reserved. 0009-3920/90/6105-0005$01.00]

Craton et al. 1529

mental improvements in communication ac-curacy to an increasing ability to analyze thelistener's perspective has not proven veryfruitful (Asher, 1979; Glucksberg et al., 1975;for a meta-analysis of this literature, see Dick-son, 1982). More recent work in this area hasemphasized the component skills required forsuccessful communication in specific tasks(e.g., Asher, 1976; Ford & Olson, 1975; Son-nenschein, 1988; Sonnenschein & White-hurst, 1984). These studies suggest that poorcommunication is often due to the child's fail-ure to adequately compare potential messagesspecifying the referent with those specifyingnonreferents.

In general, this work has focused on theidentification of objects by reference to theirintrinsic attributes (such as size, shape, orcolor). However, a referent can also be dis-tinguished from nonreferents by its extrinsicaitributes, for example, its location relativeto other objects within the environment.Clearly, both techniques are employed ineveryday life. The latter strategy is particu-larly useful when the referent object and non-referents are not easily distinguished on thebasis of their appearance. Although verbalreference to spatial location has been inves-tigated in studies of children's spatial direc-tion-giving, this research has focused primar-ily on directions specifying large-scale routes,(e.g., Cauvain & Rogoff, 1989; Plumert,Marks, & Pick, 1988; Vanetti & Allen, 1988;Waller & Harris, 1988; Weissenbom, 1980).Like referential communication studies, thesehave been concerned with developmentalchanges in the effectiveness of children's di-rections and the cognitive and linguisticchanges underlying these developments. Thefocus of spatial direction-giving research hasbeen on how children organize their direc-tions. For example, studies have examinedwhether children employ the convention, typ-ically used by adults, of taking the listenerallong an imaginary walk when describing alairge-scale space (Gauvin & Rogoff, 1989).

Spatial directions can also be analyzed ona more specific level, in terms of the spatialrelations they express and the reference ob-jects they include. Researchers in psycholin-guistics have investigated young children'sability to comprehend and produce spatial re-lational terms such as in, on, in front of, be-hind, below, between, etc. (e.g., Clark, 1980;Johnston & Slobin, 1979; Kuczaj & Maratsos,1975; Tanz, 1980). However, there has beenno research to date on what kinds of referenceobjects children spontaneously use in theirutterances about location, or whether they usethem correctly. Instead, the literature on ref-erence objects in children's statements aboutlocation has focused on how characteristics ofreference objects infiuence children's under-standing and use of spatial relational terms.For example, Kuczaj and Maratsos (1975) ex-amined the relation between whether an ob-ject has an intrinsic front or back and youngchildren's comprehension and production offront, back, and side.

In contrast to work in developmentalpsycholinguistics, several studies of the de-velopment of spatial cognition have investi-gated the reference objects that children usein order to remain oriented in a space. Re-searchers have distinguished between threespatial reference systems, or frames of refer-ence, that define spatial position with respectto (1) the self, (2) other persons, and (3) envi-ronmental landmarks (Pick, Yonas, & Rieser,1979). By placing different frames of refer-ence in confiict and observing which oneschildren rely on to perform way-finding orobject-relocation tasks, researchers have in-ferred developmental trends from reliance onself-reference to the use of other- and land-mark-based frames of reference, and from re-liance on proximal landmarks to increasinglydistal ones (e.g., Acredolo, 1976, 1977; Acre-dolo. Pick, & Olsen, 1975; Allen & Kirasic,1988; Hart & Moore, 1973; for a review, seePick et al., 1979). Children's increasing com-petence in spatial orientation tasks is de-

^ The terminology in use for describing various kinds of reference systems is somewhat confus-ing. For example, one common distinction is between egocentric and geographic frames of refer-ence. However, the term egocentric, following Piaget, is also commonly used to mean not takinganother's perspective into account. It certainly is possible to use an egocentric reference system andyet not be egocentric in Piaget's sense. I could, for example, tell someone else that something is infront of me or to my right. This should enable them to localize that something. Such a directionwould be neutral with respect to whether I am egocentric in Piaget's sense. In the present paper, wewill use "self reference system" to refer to the so-called egocentric frame of reference. The termallocentric is often used to mean anything but a self reference system. However, it seems moreprecise, following the Latin root of the word, to use allocentric to refer to frames of reference basedin another person. That is, as ego refers to the self, allo- would he used to refer to the other person.Then geographic would be used to refer to non-person-based reference systems. Finally, proximaland distal frames of reference are typically used to refer to reference systems which are less or more

1530 Child Development

scribed in terms of the reference system used.As Pick et al. (1979, p. 130) note, environmen-tal landmarks are more important than ani-mate reference objects like oneself or otherpeople when the goal is to remain spatiallyoriented while moving through a space. Simi-larly, when the task involves remainingoriented in an enclosed space, more distal(and typically larger) environmental land-marks (e.g., the walls of a room) are also lesslikely to change position than are the proxi-mal landmarks contained within the space(e.g., furniture) and are consequendy more re-liable. Pick et al. propose that as childrenbroaden their attentional focus with age theybecome capable of using increasingly distantreference objects.

The present study represents a newapproach to the systematic investigation ofthe development of verbal communicationabout spatial location. The aim of the studywas twofold: (1) to examine developmentalchange in children's use of frames of refer-ence in a small-scale spatial direction-givingtask, and (2) to compeire the effectiveness ofchildren's directions in environmental con-texts that differed in the availability of poten-tial reference objects. Four-, 6-, and 8-year-oldchildren attempted to specify verbally whichof several identical cups contained a hiddenobject. Children in one condition sat acrossfrom an adult listener in a room that had awide variety of potentially informative refer-ence objects, specifically, the child, the lis-tener, and distinctive landmarks proximal anddistal to the cup array. In the second condi-tion, only the child and "the listener could beused to construct an effective direction—thelandmarks, while present, no longer differ-entiated opposite sides of the room or the cuparray.

The effectiveness of directions was ex-pected to increase with age. The spatial refer-ence systems literature and studies of the or-der of acquisition of spatieil terms suggestedtwo predictions about developmental trendsin the use of reference objects. First, the no-tion of a developmental shift from self- toother- or landmark-based frames of referencesuggested that the frequency of self-referencein spatial directions would decline with age

relative to other frames of reference. This pre-diction, however, seemed less likely to holdfor directions about the lateral dimension ofthe cup array in the present task. Because theability to use left and right is particularlydifficult for children and develops after other{front-back and up-down) spatial relationalterms (Harris, 1972), young children mightnot attempt to use themselves or the listeneras reference objects when communicatingabout the lateral dimension (e.g., "It's on my/your left"). This implied that the effectivenessof younger subjects' directions about the lat-eral dimension would depend on their abilityto use differentiating landmarks in place ofleft and right. Second, the notion of a proxi-mal-to-distal shift suggested that with differ-entiating landmarks present, younger chil-dren would be limited to using referenceobjects proximal to the target location. Olderchildren, in contrast, should be able to incor-porate a greater proportion of distal referenceobjects in their directions.

Experiment 1

METHOD

SubjectsSubjects were 20 preschoolers from a

university laboratory nursery school and 20first graders and 20 third graders from a mid-dle-class metropolitan public school. Therewere equal numbers of boys and girls in eachexperimental condition. Mean ages of thegroups were: 4-7 (range: 3-11 to 5-3), 6-8(range: 6-2 to 7-4), and 8-8 (range: 8-4 to 9-5).

DesignEach child attempted to specify verbally

the location of a hidden toy in one of twoexperimental conditions. Ten of the childrenin each age group gave directions in a differ-entiated condition, which offered a rich as-sortment of distinctive markings that poten-tially could be related to the hiding location.The other half of the children gave directionsin an undifferentiated condition, which hadsimilar but nondistinctive markings.

ApparatusThe experimental room, shown in Figure

1, measured 14 x 7 feet (4.27 x 2.13 m) andwas constructed of uniform white panels.

remote from the subject Thus, a self reference system is a very proximal one. However, the proxi-mal-distal distinction can also be made in relation to the focus of the task. Thus, for a task in whichthe goal is to orient the self, proximal does mean close to the self. The focus of the task in the studiesdescribed below is a hiding location across the room from the subject. Therefore, in this discussion,proximal will be used to mean close to the focus of the task and distal will be used to mean far fromthe focus of the task. As will be seen, in this Sense in this study, a self reference system would alsobe a distal one.

Craton et al. 1531

Differentiated Undifferentiated

FIG. 1.—Room layouts for experimental conditions

with six equally spaced doorways, 24V2 inches(62.2 cm) wide, covered with cloth curtains.Tlie ceiling, 7 feet (2.13 m) high, was madefrom translucent cloth material. The roomcontained a chair for the subject at one endand another chair for the adult experimenterwho was the "listener" at the other end. Di-rectly in front of the listener was a 14-inch(35.6 cm) high table, thfe top measuring 19^2X 22V2 inches (49.5 x 57.1 cm). The tablewas placed away from the subject to discour-age pointing at the hiding location. The cupsused to form the hiding arrays on the tableweire opaque blue and 5 inches (12.7 cm)high. The objects used for hiding were smalltoys.

The differentiated and undifferentiatedexperimental conditions differed in the dis-tinctiveness of the colors of curtains in thedoorways and the colors of strips of tape onthe edges of the table. In the differentiatedcondition, opposite sides of the table androom were marked by tape or curtains of dif-ferent colors. In the undifferentiated con-dition, opposite sides of the room and ta-ble were marked with the same colors (seeFig. 1).

ProcedureA second adult experimenter, the "ob-

server," told each subject that he or she

would be playing a number of hiding andfinding games in which the observer wouldhelp the child hide a small toy under one of anumber of cups while the listener was out ofthe room. After the toy was hidden, the childtook the seat across the room from the table,and the listener was called back into theroom. The observer then stood slightly be-hind and to the child's right side while thechild gave directions to the listener.

The child was given the instructions:"Tell [the listener's name] where the toy is sohe can find it as quickly as possible." Chil-dren were instructed not to point to the toy'slocation. If the listener judged the child's firstverbal direction in each trial to be effective,the toy was revealed and the child praised.If the child's direction was inadequate tospecify the toy's location precisely, the lis-tener prompted the child to provide moreinformation or try again (e.g., "I can't find ityet. Can you tell me something else aboutwhere it is?"). If the direction was still inef-fective after two such prompts, the listener"guessed" at the toy's location, basing thechoice as closely as possible on the informa-tion the child had given. If the "guess" wasincorrect, the child was then given a chanceto supplement the direction further. Even-tually, the listener revealed the toy, and thechild was praised for his or her efforts.

1532 Child Development

Array

Array 2

Array 3

Array 4

Array 5

OO

Necessary Distinctions

Front-Back (FB)

Left-Right (LR)

Left-Right (LR)Middle-End (ME)

Front - Back (FB)Middle-End (ME)

Front-Back (FB)Left -Right (LR)

FIG. 2.—Cup arrays, shown in order of presentation, with distinctions necessary to specify hidinglocation.

There were 16 trials, including all possi-ble hiding locations in five different cup ar-rays. Each array required the child to specifythe target object's location with reference toeither one or two of the following dimensionsof the cup array: front-back (FB), left-right(LR), and middle-end (ME). The five cup ar-rays and the kinds of spatial distinction sub-jects needed to make for each array are shownin Figure 2.

Subjects were first given two easy prac-tice trials, in which the toy was hidden underone of a pair of differently colored cups ar-rahged as in array 2 (see Fig. 2). All subjectsperformed both practice trials correcdy. Be-cause pilot work had indicated that some ar-rays were quite difficult for preschoolers, theorder of presentation was designed so that theyoungest subjects would not be overly dis-couraged early in the session if they failed togive effective directions for difficult arrays.Thus, all subjects received the cup arrays inthe same order, shown in Figure 2.

Coding and AnalysisEach child's directions for all 16 trials

were transcribed from audiocassette tape re-

cordings. The present report is based on thecoding of subjects' directions prior to anyprompting. Two of the authors coded sub-jects' directions on each of the 16 trials foreffectiveness and for the fypes of referenceobjects used. For all five cup arrays, a direc-tion was coded as effective if the subjectunambiguously specified the target locationwith respect to all the relevant dimensions(some combination of FB, LR, and ME) forthat array. In addition, codings for effective-ness were done separately for the FB and LRdimensions of the four-cup 2 x 2 array (ar-ray 5, Fig. 2).

The types of reference objects included:(1) Self ("it's on my right hand"); (2) Listener("it's the one on your side"); (3) Tape ("theone near the red tape"); (4) Curtains ("by thered curtain"); (5) Cup Array ("it's one ofthe ones in the middle"); (6) Object-inside (anobject inside the experimental room, "it's bythe leg on the table"); (7) Object-outside (anobject outside the experimental room, "it'son the same side as the parking lot"); (8)Nonspecific (coded when the child appar-endy tried to use a reference object, but the

Craton et al. 1533

Undifferenliated Differentiated

75%

Mean %Effective 4o%

Directions

8YRS.

FIG. 3.—Experiment 1: Mean percent effective directions as a function of age and differentiationcondition.

coder was unable to determine which type:"by the blue" or "one of the cups on theleft"). Reference points were coded as pres-ent regardless of whether the direction waseffective.

Reliability for each variable was deter-mined by dividing the number of trials thatthe coders scored identically by the totalnumber of trials coded for six randomly se-lected subjects (10% of the sample). Percentagreement for the effectiveness variable was85%; agreement for eight reference-pointvariables ranged from 75% to 100%, with amean of 92%. Only the nonspecific variablehad an intercoder reliabilify less than 80%.

RESULTS AND DISCUSSION

EffectivenessFigure 3 shows the mean percentage of

effective directions across all 16 trials for eachage group in the two differentiation condi-tions. A 3 (age) x 2 (differentiation condition)X 2 (sex) ANOVA for effectiveness revealedsignificant main effects of age, F(2,48) =40.91, p < .001, condition, F(l,48) = 5.03, p <.05, and sex, F(l,48) = 6.23, p < .05, MS error= 9.31. Post hoc tests (Tukey's HSD, alpha =.05) indicated that the percentage of effectivedirections differed for all age comparisons (4-year-olds, 19%; 6-year-olds, 50%; 8-year-olds,72%). Effectiveness was higher in the differ-entiated condition than in the undifferen-tiated condition (53% and 42%, respectively),and girls gave a higher proportion of effectivedirections than boys (53% and 41%, respec-tively). These results are consistent with ourhypothesis of general improvement with age

and indicate that children performed betterwhen distinctive landmarks were present.

Effectiveness for the FB and LR dimen-sions.—Two analyses examined the hypothe-sis that children would have more difBculfycommunicating about the left-right than thefront-back dimension. Because the cup arraysdiffered in number of cups and thus in thenumber of dimensions that had to be coor-dinated on any given trial, these analyses alsoincluded an array type variable. This allowedus to examine whether children had moredifficuify with the relatively complex four-cuparrays than the two-cup arrays. The first analy-sis compared effectiveness for the LR and FBtwo-cup arrays (arrays 1 and 2) with effec-tiveness for the LR and FB dimensions of thefour-cup 2 x 2 array (array 5; see Fig. 2). Thiswas a 3 (age) x 2 (differentiation condition)X 2 (dimension: FB vs. LR) X 2 (array type:two-cup vs. four-cup 2 x 2 ) ANOVA withrepeated measures on the last two factors.The second analysis was identical to the first,except that it compared effectiveness for theLR and FB two-cup arrays with effectivenessfor the LR and FB four-cup linear arrays (ar-rays 3 and 4 in Fig. 2). Both analyses wereconducted on the mean percentage of effec-tive directions.

The first analysis revealed a main effectof age, F(2,54) = 23.19, p < .001, and a signifi-cant age X dimension interaction, F(2,54) =3.43, p < .05. There were no significant ef-fects for the array fype factor, indicating thatchildren performed as well in specifying theFB and LR dimensions for the four-cup 2 x 2array as they did in specifying location for

1534 Child Development

these dimensions in the two-cup arrays. Posthoc comparisons (Tukey's HSD, alpha = .05)showed that 4-year-olds gave significantlybetter directions about the FB dimensionthan the LR dimension (49% and 0.1%, re-spectively). In contrast, the mean scores onthe FB and LR dimensions did not differ sig-nificantly for 6-year-olds (71% and 47%, re-spectively) or for 8-year-oIds (86% and 74%,respectively). Eight-year-olds gave signifi-cantly better directions than the 4-year-oldson both the FB and LR dimensions. Six- and8-year-olds' mean scores did not differ, how-ever. Six-year-olds gave a greater percentageof effective directions than the 4-year-olds forthe LR dimension (47% and 0.1%, respec-tively), but their mean scores for the FB di-mension did not differ significandy (71% and49%, respectively). These results indicate thatcommunicating about the two-cup LR arrayswas particularly difficult for the 4-year-oldchildren.

The second analysis compared effective-ness for the two-cup and four-cup linear ar-rays (in Fig. 2, arrays 1—4). This analysis re-vealed main effects of age, F(2,54) - 27.92, p< .001, differentiation condition, F(l,54) =5.13, p < .05, dimension, F( 1,108) = 56.06, p< .001, array fype, F(l,108) = 5.10, p < .05,and a significant age X dimension X arraytype interaction, F(2,108) = 3.6, p < .05. Posthoc comparisons (Tukey's HSD, alpha = .05)showed that the mean score for 8-year-olds(77%) was significandy greater than that for 4-year-olds (26%) but not significantly differentfrom that for 6-year-olds (54%). Performancewas higher in the differentiated condition(59%) than in the undifferentiated condition(46%). Children gave a greater percentage ofeffective directions for FB arrays than for LRarrays (68% and 36%, respectively) and for the

two-cup than for the four-cup arrays (56% and49%, respectively).

Table 1 shows the data, collapsed for dif-ferentiation condition. Because Tukey's HSDtest is unnecessarily conservative when thereare a large number of means to compare(Hays, 1981), the three-way interaction wasanalyzed using the Newman-Keuls post hoccomparisons test (alpha = .05). On the FBtwo-cup array, the mean score of 8-year-oldswas significantly higher than that of 4-year-olds but not significandy different from that of6-year-olds. Six- and 8-year-olds' scores on theFB four-cup array did not differ significantlybut were both significantly higher than that of4-year-olds. On both the LR two-cup and theLR four-cup arrays, 8-year-olds' mean scoreswere significantly higher than those of 6-year-olds, which in turn were significantly higherthan those of 4-year-olds.

Scores for the LR two- and four-cup lin-ear arrays did not differ significantly for anyage group, nor did scores for the FB two- andfour-cup arrays. The mean scores for 4- and 6-year-olds were significantly higher on bothtypes of FB than LR arrays. These results sug-gest that the LR dimension was particularlychallenging for the 4- and 6-year-old children.The results also indicate that 8-year-olds hadmore difficuify with the LR four-cup lineararray than with the FB arrays. Although 8-year-olds' performance on the LR two-cup ar-ray did not differ from the FB two- or four-cuparrays, their mean scores on both FB arrayswere significantly greater than that on the LRfour-cup array.

Landmarks and effectiveness for the LRdimension.—To test the prediction thatyoung children would communicate moresuccessfully about LR relations when differ-

TABLE 1

EXPERIMENT 1: MEAN PERCENT EFFECTIVE DIRECTIONS AS A FUNCTION OFAGE, DIMENSION, AND ARRAY TYPE

DIMENSION/ARRAY TYPE

Front-Back Left-Right

AGE GROUP 2 Cups 4 Cups 2 Cups 4 Cups

4 years (n = 20) 55 39 5 4(46) (47) (22) (25)

6 years (n = 20) 72 74 42 27(30) (36) (37) (43)

8 years (n = 20) 82 87 77 60(29) (25) (38) (35)

NOTE.—Standard deviations are in parentheses.

Craton et al. 1535

entiating landmarks were available, threeplanned comparisons were done on the meanpercentage of effective directions for LR ar-rays (arrays 2 and 3; total number of trials =6) in the differentiated and undifferentiatedconditions. The results showed that 6-year-olds gave\a greater proportion of effectivedirections in the differentiated than in theundifferentiated condition (47% and 18%, re-spectively, t[19] = 2.35, p < .05). In contrast,neither 4- nor 8-year-olds gave a greater pro-portion of effective directions in the differ-entiated than in the undifferentiated condi-tion (4-year-olds, 8% and 0%; 8-year-olds,68% and 63%, respectively). Thus, it seemsthat while 4-year-oIds were unable to makeuse of the presence of distinctive landmarksto specify the LR dimension, 6-year-oldsbenefited from these landmarks. Eight-year-olds, in tum, were able to produce as manyeffective directions in the absence of distinc-tive landmarks as they did when landmarkswere available. This suggests that they usedthemselves or the listener as reference objectsin order to specify the lateral dimension.

Use of Reference Object TypesThe major aim of this study was to inves-

tigate age-related changes in the types of ref-erence object used in spatial directions. Thatis, was the increase in the number of effectivedirections with age reported above accom-panied by the implementation of a singlestrategy of reference object use, or was there ashift in strategy with age?

The number of trials (total number trials= 16) in which each child used a given typeof reference object was calculated. Becausethe overall frequency of reference object usevaried with age (4-year-olds, M = 19; 6-year-olds, M = 26; 8-year-olds, M = 25), analyseswere conducted on proportional use of refer-ence object types computed for each subject.Meim percent data are presented in Table 2.These were analyzed using the multivariateapproach for repeated measures (O'Brien &Kaiser, 1985).

The MANOVA included three between-subjects factors, age (3) x differentiation con-dition (2) X sex (2), for the eight types ofreference objects. There were significant mul-tivairiate main effects of age, F(14,96) = 3.32,p < .001, condition, F(7,48) = 4.03, p < .001,and a significant multivariate age x conditioninteraction, F(14,96) = 2.55, p < .005. Theunivariate tests for the eight reference objecttypes and post hoc comparison tests (Tukey'sHSD, alpha = .05) are reported below.

SelfThe univariate ANOVA for self refer-

ences revealed a significant main effect ofage, F(2,54) = 6.55, p < .005, and a significantage X condition interaction, F(2,54) = 3.20, p< .05. Post hoc tests showed that the propor-tion of directions in which 8-year-olds usedthemselves as reference objects (22%) wassignificantly greater than that for both 6-year-olds (14%) and 4-year-olds (9%). The meanscores for 6- and 4-year-olds did not differsignificantly. In addition, 8-year-olds usedthemselves as a reference object significantlymore often in the undifferentiated than in thedifferentiated condition. The means for 4- and6-year-olds in the two differentiation condi-tions did not differ (see Table 2).

ListenerThe univariate ANOVA for use of the lis-

tener revealed a significant main effect of age,F(2,54) = 3.98, p < .05. Post hoc tests showedthat the percentage of directions in which 8-year-olds used the listener as a reference ob-ject (27%) was significandy greater than thatfor 4-year-olds (15%), but did not differ sig-nificantly from that for 6-year-olds (20%). Useof listener did not differ significantly for 4-and 6-year-olds. The data in Table 2 indicatethat reference to the listener occurred in arelatively high proportion of directions foreach age group. The reasons for this were ex-amined in Experiment 2, reported below.

Landmeirks /Tape.—The univariate ANOVA for use

of the proximal tape landmark revealed asignificant main effect of condition, F(l,54) =4.78, p < .001, and a significant age x condi-tion interaction, F(2,54) = 3.92, p < .005.Children referred more to the tape in the dif-ferentiated than in the undifferentiated condi-tion (15% and 2%, respectively). Eight-year-olds referred to the tape more often in thedifferentiated than in the undifferentiatedcondition, but use of tape in the two differ-entiation conditions did not differ signifi-cantly for either the 4- or 6-year-oIds (seeTable 2).

Curtain.—The univariate ANOVA forreferences to the distal curtain landmark re-vealed significant main effects of age, F(2,54)= 6.11, p< .005, condition, F(l,54) = 4.78, p< .05, and a significant age X condition in-teraction, F(2,54) = 6.19, p < .005. Six-year-olds referred to the curtains in a greater per-centage of their directions than did either the4- or 8-year-olds (11%, 3%, and 3%, respec-tively). The curtains were used more in thedifferentiated than undifferentiated condition

1536 Child Development

TABLE 2

EXPERIMENT 1: MEAN PERCENT DIRECTIONS INCLUDING REFERENCE OBJECTS AS A FUNCTION OF AGEAND DIFFERENTIATION CONDITION

REFERENGE OBJECT

Cup Obj. Obj.AGE GROUP/CONDITION Self Listener Tape Curtain Array In Out Nonspecific

4 years (n = 20):Differentiated 8 17 8 1 39 0 0 27

(12) (13) (15) (3) (19) (0) (0) (19)Undififerentiated 10 13 3 5 33 0 0 36

(9) (11) (4) (6) (17) (0) (0) (25)6 years (n = 20):

DifFerentiated 15 17 11 18 26 0 0 12(6) (6) (6) (13) (12) (0) (1) (11)

Undififerentiated 13 23 4 3 32 9 1 14(10) (12) (7) (7) (16) (15) (3) (15)

8 years (n = 20):Dififerentiated 14 20 25 4 25 0 0 12

(11) (17) (18) (5) (10) (1) (0) (8)UndifFerentiated 29 33 0 1 27 6 1 3

(13) (13) (0) (2) (7) (12) (2) (5)

NOTE.—Stanclard deviations are in parentheses.

(8% and 3%, respectively). Analysis of the ageX condition interaction showed that 6-year-olds used the curtains more than either the 4-or 8-year-olds in the differentiated condition.Reference to the curtains was quite infre-quent for the 4- and 8-year-olds and did notdiffer significantly for the two differentiationconditions (see Table 2).

Proximal-to-distal shift.—Three plannedcomparisons compared the mean number ofdirections (out of 16) containing references tothe proximal tape with the mean number ofdirections containing references to the distalcurtains. These analyses were conductedwithin each age group on directions made bysubjects in the differentiated condition. Four-year-olds' reference to the tape and curtainswas infrequent and the means did not differsignificantly (1.6 and .3, respectively). Therewas no significant difference in the means for6-year-olds' references to the tape and cur-tains (3.3 and 5.1, respectively). Eight-year-olds, in contrast, used a significantly greaternumber of tape than curtain references (6.6and .9, respectively,- ^[9] = 3.596, p < .005).

Thus, by 6 years of age, children wereable to incorporate the distal curtains intotheir directions. Interestingly, while 6-year-olds in the differentiated condition referred tothe curtains in a greater proportion of theirdirections than the 4-year-olds, they also useda greater proportion of curtain references thanthe 8-year-olds. Presumably the 8-year-olds

were also capable of using the distal curtainsin their directions. However, they did so in-frequently and showed a strong preferencefor using the proximal tape.

Use of landmarks for the LR dimen-sion.—Would young children's difficulty inusing left and right lead them to attempt tospecify left-right relations by referring tolandmarks rather than to themselves or theirlistener? Six planned comparisons testedwhether the percentage of directions contain-ing references to landmarks (curtains + tape)differed from percentage use of person refer-ences (self + listener) within each age group.These comparisons were conducted indepen-dently for directions given in the differenti-ated condition on linear FB arrays (arrays 1and 4 in Fig. 2) and linear LR arrays (arrays 2and 3 in Fig. 2). For FB arrays, 4- and 6-year-olds used significantly more person refer-ences than landmark references (4-year-olds:M = 21% and 4%, respectively, f [9] = 1.98, p< .05; 6-year-olds: M = 44% and 16%, t[9] =3.07, p < .01). For LR arrays, 4-year-olds' useof both landmark (M = 10%) ahd person (M= 1%) references was infrequent and did notdiffer significantly. In contrast, 6-year-oldsused landmark references for LR arrays (M =33%) significantly more often than person ref-erences (M = 3%), t[9] = 4.01, p < .005).Eight-year-olds' use of landmark and personreferences did not differ significantly foreither FB arrays (20% and 33%, respectively)or for LR arrays (23% and 28%, respectively).

Craton et al. 1537

indicating a mixed strategy for the specifica-tion of both dimensions.

Cup ArrayReferences to the cup array (e.g., "it's in

tlie middle" or "it's next to the one on theend") were used in a high percentage of di-r«;ctions at all ages and showed no effect ofage or differentiation condition (see Table 2).

Objects-Inside and Objects-OutsideThe univariate ANOVA for references to

objects in the room revealed a significantmain effect for differentiation condition,F(l,54) = 6.72, p < .05. As might be ex-pected, children used a higher proportion ofreferences to objects in the room (usually theobserver) in the undifferentiated condition(5%) than in the differentiated condition (0%).

NonspecificThe univariate ANOVA for nonspecific

references revealed a significant main effectfor age, F(2,54) = 12.23, p < .001. Post hoctests showed that the percentage of directionswith inadequately specified reference objectswas significantly greater for 4-year-olds (32%)thian for both 6- (13%) and 8-year-olds (8%).Use of nonspecific reference objects by 6- and8-year-olds did not differ significantly.

Reference Use for LR and FR DimensionsThe results of the planned comparisons on

use of landmarks versus person references forthie FB and LR dimensions, reported above,suggest that dimension is an important factor

in determining the reference objects that chil-dren incorporate into their directions. Four-and 6-year-olds used more person than land-mark references for FB arrays, and 6-year-oldsshowed the opposite pattem for LR arrays. Anadditional multivariate analysis on propor-tional use of self, listener, landmark (tape andcurtain combined), and nonspecific referenceobjects examined whether the dimension ofthe cup array (FB, LR) and the presence orabsence of distinctive landmarks influencedthe frequency of use of particular referenceobject types. This was a 3 (age) x 2 (differ-entiation condition) x 2 (dimension: FB vs.LR, arrays 1-4) MANOVA with repeatedmeasures on the last factor. Percentages werecomputed without including the cup arrayreferences since our interest was in the use ofreference objects external to the cup array it-self. The data are shown in Table 3. Therewere significant multivariate main effects ofage, F(6,102) = 6.07, p < .001, of dimension,F(4,50) = 22.33, p < .001, and a significantage X dimension interaction, F(8,100) =2.10, p < .05.

Of particular interest were several signifi-cant univariate effects involving the dimen-sion factor, including main effects of refer-ences to self, F(l,53) = 27.60, p < .001,listener, F(l,53) = 43.82, p < .001, landmarks,F(l,53) = 9.84, p < .005, and nonspecific ref-erence objects, F(l,53) = 24.72, p < .001. In-terestingly, the direction of these effects dif-fered for the different types of reference

TABLE 3

EXPERIMENT 1: MEAN PERCENT DIRECTIONS INCLUDING FRAMES OF REFERENCEAS A FUNCTION OF AGE AND DIMENSION

FRAME OF REFERENCE

AGE GROUP/DIMENSION Self Listener Landmarks Nonspecific

4 years (n = 20):Front-back 11

(16)Left-right 1

(3)6 years (n = 20):

Front-back 17(12)

Left-right 0(2)

8 years (n = 20):Front-back 18

(11)Left-rigbt 12

(14)

21(19)

3(9)

25(13)

5(10)

20(10)14

(17)

4(10)

7(13)

12(18)23

(17)

9(13)14

(16)

17(19)36

(27)

3(7)15

(15)

3(4)10

(13)

NOTE.—Standard deviations are in parentheses.

1538 Child Development

objects. As Table 3 shows, proportional use ofself and listener references by children of allages was higher for directions about FB arraysthan directions about LR arrays. There was asignificant univariate age x dimension in-teraction for references to the listener, F(2,53)= 4.35, p < .05. Post hoc analyses (Tukey'sHSD, alpha = .05) showed that 4- and 6-year-olds used a greater proportion of listener ref-erences in their directions about the FB di-mension than the LR dimension. In contrast,there was no difference in the percentage oflistener references in the 8-year-olds' direc-tions about the FB and LR dimensions. Table3 reveals a similar trend for references to self,although the age x dimension interactionwas not significant, F(2,53) = 2.37, p = .10.

The data for references to landmarks con-trast sharply with those for self and listenerreferences. At each age, a higher proportionof landmarks were used in directions aboutLR arrays than those about FB arrays. Not sur-prisingly, there was also a significant main ef-fect of condition, F(l,53) = 4.17, p < .05, withlandmarks being used in a greater percentageof directions in the differentiated condition(15%) than in the undifferentiated condition(8%).

In summary, 4-year-olds performed mod-erately well with the FB dimension, but theywere rarely able to accurately specify locationfor the LR dimension. Both 4- and 6-year-oldsgave more effective directions for the FB ar-rays than the LR arrays. Eight-year-olds, how-ever, performed comparably on both dimen-sions, with the exception of the LR four-cuplinear array (array 3, see Table 1). It is un-likely that 8-year-olds' difficulty with array 3was due solely to an increase (from two tofour) in the number of cups, since the sameincrease did not disrupt their performance onthe FB dimension for arrays 4 and 5. Nor doesthe additional requirement of a ME distinc-tion completely account for this finding, sincethis w as also a requirement for the FB four-cup linear array. Instead, the data suggest thatLR relations were problematic even for the 8-year-olds, but that this was only evident whenthe task demands were increased (see Harris,1972).

The patterns of reference-object use ob-served here suggest that the increasing com-petence of children with age refiects shifts inthe strategies used for communicating aboutspatial location. In addition, the patterns of

reference-object use differed for the FB andLR dimensions. Even when differentiatinglandmarks were available, 4- and 6-year-oIdsused references to persons to specify locationin FB arrays. The correlations between effec-tiveness and use of person references for theFB dimension were quite high and statisti-cally significant for both age groups (4-year-olds: r = .81; 6-year-olds: r = .79, p < .01),indicating that children successfully executedthis person-based strategy. While 4-year-oldsdid not attempt to deal with LR arrays byswitching to a landmark-based strategy, 6-year-olds did. Six-yeeir-olds' performance withLR arrays benefited from the presence ofdistinctive landmarks. They constructed agreater number of effective directions for LRarrays when the landmarks were distinctive,and thus useful for specifying location, thanwhen they were not distinctive. The correla-tion for 6-year-olds between effectiveness anduse of landmarks for the LR dimension in thedifferentiated condition was quite high (r =.71, p = .01), indicating that they were suc-cessful in utilizing this landmark-based strat-egy. Increasing competence between theages of 4 and 6 years for communicating aboutthe LR dimension appears to be due to a shiftin strategy and not to more effective use oflandmarks in spatial directions. Unlike theyounger children, 8-year-oIds used a combi-nation of person and landmark references intheir directions about both FB and LR arrays.This older group was able to construct asmany effective directions for the LR arrayswhen landmarks were distinctive as whenthey were not, suggesting that they were suc-cessful at using themselves and their listeneras reference objects when communicatingabout the LR dimension.

The findings that 6-year-olds referred tothe curtains more often and 8-year-olds usedthe tape more often in the differentiated thanundifferentiated condition indicate that theseage groups recognized the usefrilness of dis-tinctive, as opposed to nondistinctive, land-marks in describing spatial location. Four-year-olds' use of landmarks, on the otherhand, was infrequent in both differentiationconditions. It may have been that the salienceof the environmental cues in this experimen-tal situation was insufificient to elicit their at-tention (see Acredolo, 1976; Acredolo &Evans, 1980). A follow-up experiment failedto provide convincing evidence for this hy-pothesis, however.^

^ Well-known cartoon characters were added to the color-differentiated tape and curtains, eachcartoon character being paired with a particular color (see Fig. 1). Planned comparisons showed that

Craton ct al. 1539

Another result from Experiment 1 wasthat children of all ages referred to the lis-tener in a relatively high proportion of theirdirections. Was the frequent use of the lis-tener due to his or her proximity to the hidinglocation, or was use of the listener promptedin some other way by the communicative na-ture of this task? A second experiment inwhich the table was moved away from thelistener explored the first possibility.

Experiment 2

METHOD

SubjectsTwenty 6-year-olds (mean age: 6-10;

range: 6-3 to 7-7) and 20 8-year-olds (meanag;e: 8-11; range: 8-5 to 9-6) from a metropoli-tan parochial school participated, with equalnumbers of girls and boys in each experimen-tal condition.

Design and ProcedureThe experimental room, procedure, cod-

ing, and analysis were the same as in Ex-periment 1. Children gave directions in theoriginal undifferentiated condition, with thecup-array table located either directly in frontof the listener {proximal listener condition) asin Experiment 1 or on the opposite side of theroom, 27 inches (68.6 cm) in front of the sub-ject's chair {distal listener condition). If theproximity of the listener to the cup array inExperiment 1 accounts for children's frequentuse of listener references, then one would ex-pect a lower proportion of listener referencesin the distal listener condition than in theproximal listener condition.

Coding reliability for eight (20%) of thesubjects was 90% for the effectiveness vari-able and 93% for the listener reference-objectvariable.

RESULTS AND DISCUSSION

EffectivenessA 2 (age) X 2 (condition: proximal vs.

distal listener) X 2 (sex) ANOVA for effec-tiveness revealed a significant main effect ofage, F(l,32) = 23.90, p = .001, and a mar-ginally significant main effect of condition,F(l,32) = 3.92, p = .056. Eight-year-oldsgave a greater percentage of effective direc-

tions than the 6-year-oIds (75% and 37%, re-spectively), and subjects' performance wasslightly better in the distal than in the proxi-mal listener condition (63% and 48%, respec-tively).

Use of Listener as Frame of ReferenceReversing the relative distance of the

child and the listener from the cup array didnot result in a decrease in proportional use ofthe listener. In fact, a 2 (age) x 2 (proximal vs.distal listener condition) X 2 (sex) ANOVAon the mean percentage of directions includ-ing listener references revealed a significantmain effect of condition, F(l,32) = 6.59, p <.05; MS error = 7.01, with a greater propor-tion of references to the listener in the distallistener condition than in the proximal lis-tener condition (see Fig. 4). There was also asignificant main effect of age, with 8-year-oldsproducing more listener references than 6-year-olds, F(l,32) = 23.59, p = .001.

Thus, the results of Experiment 2 do notsupport the hypothesis that the frequent useof the listener as a reference object in Experi-ment 1 was due to the listener's proximity tothe cup array. Moving the listener fartherfrom the cup array resulted in a higher, not alower, proportion of references to the listener.In addition, children performed better whenthe cup array was close to them and far fromthe listener. What might account for these ef-fects? The increase in effectiveness may havebeen due to the location of the hidden toybeing easier to encode and remember whenthe cup array was closer because it could beseen with less effort. If this is true, the childmay be able to devote more attention to effec-tively solving and coordinating other require-ments of the task. In addition, children mayhave been aware that the listener might havesome difficulty seeing the cups when the ta-ble was close to the child and consequendymay have tried to make the listener's taskeasier by encoding the toy location in refer-ence to the listener. Future studies that inde-pendently vary the distances of the listenerand the child from the cup array may help todetermine how the absolute distance of thelistener (or child) from the cup array, as wellas the relative distance of listener and childfrom the array, affects children's performancein this task.

the mean percentage of preschoolers' directions including tape references in this high-saliencecondition (M = 12%) and the differentiated condition from Experiment 1 (M = 8%) did not differsigniflcantly, nor did proportional use of curtain references differ across these two conditions (highsalience, M = 2%; undifferentiated, M = 1%). Finally, the mean percentage of effective directionsacross all 16 trials did not differ signiflcantly (high salience, M = 29%; undifferentiated, M = 24%).

1540 Child Development

Proximal Listener B Distal Listener

36%40%

30% •

Mean %DirectionsIncluding 20% •Listener

Reference1 0 % • •

0%First Third

GradeFIG. 4.—Experiment 2: Mean percent directions including listener reference as a function of age and

listener position.

General Discussion

The patterns that emerged in the types ofreference objects children used to communi-cate spatial location and their varying suc-cesses in producing effective directions pro-vide a new perspective on developmentalchanges in spatial frames of reference. Takentogether, the results illustrate that (1) al-though children's overall performance im-proved with age, the rate of improvement dif-fered for directions about the front-back andleft-right dimensions, and (2) the frames ofreference that children incorporated into theirdirections changed with age and differed fordirections about the front-back and left-rightdimensions. Four-year-olds gave effective di-rections for the front-back dimension abouthalf of the time but hardly ever succeededwith the left-right dimension. Their successwith the front-back dimension appears torefiect their use of themselves and their lis-tener as reference objects in their directions.Use of landmarks for the front-back dimen-sion was much lower in comparison. Not sur-prisingly, 4-year-olds almost never referred tothemselves or their listener in their directionsabout the left-right dimension. However, theydid not compensate for their apparent inabil-ity to use self or listener references by at-tempting to use distinctive landmarks. Nordid they use distinctive landmarks when theywere made more salient (see n. 2).

Six-year-olds, on the other hand, con-structed effective messages about the front-back dimension about three-quarters of thetime and gave a comparable percentage of ef-

fective directions for the left-right dimensionas 4-year-olds did for the front-back dimen-sion. Six-year-olds' success with the front-back dimension appears to reflect a relativelyhigh proportion of references to themselvesand their listeners, along with a greater pro-portion of landmark references compared to4:-year-olds. Like the 4-yeeir-oIds, 6-year-oldsrarely used themselves or their listener tospecify location for the left-right dimension.However, they were able to compensate tosome extent for their apparent difficulty in us-ing the terms left and right by relying moreheavily on the landmarks as markers for leftand right. This switch from person referencesin directions about the front-back dimensionto landmark references in directions about theleft-right dimension helps explain why 6-year-olds did better than the 4-year-olds withthe left-right dimension.

In general, the 8-year-olds performedequally well with front-back and left-right ar-rays, with the exception of the four-cup left-right linear array, as noted above. The per-centage of effective directions by 8-year-oldsfor the left-right dimension was comparable tothat of 6-year-olds for the front-back dimen-sion. In contrast to the younger children, 8-year-olds referred to themselves and their lis-tener to specify location iri the left-right arraysby giving directions such as, "It's the last oneon your right." This increase in references tothemselves and their listener was accom-panied by a decrease in the percentage oflandmark references relative to the 6-year-olds.

Craton et al. 1541

These age changes in effectiveness forthe front-back and left-right dimensionsmerge nicely with age changes in patterns ofreference-object use. How should the agechsmges in use of reference objects observedhere be interpreted? The developmentaltrends for use of reference objects differedfrom those reported in the spatial cognitionliterature (Acredolo, 1976, 1977; Acredolo etal., 1975; see Pick et al., 1979). First, therewas no evidence for a developmental shiftfrom the use of self- to other person- or land-mark-based frames of reference. Instead, ref-erences to self increased with age. Second,there was not a shift from use of proximal todistal frames of reference; in fact, just the op-posite occurred in this task. Six-year-olds re-fenred more frequently to the distal curtainsthan to the proximal tape, and 8-year-olds re-fenred more to the proximal tape than to thedistal curtains.

The contrast between the present resultsand those reported in other spatial cognitionstudies illustrates the need for researchers toconsider how task demands and develop-mental level mutually constrain reference-system use. Several task variables are likely tohave played a role in our communication task.First, successful communication of locationrequires the child to provide unambiguous in-fonnation to the listener. One aspect of thisrequirement is the need to specify unambigu-ously whatever reference objects one is at-tempting to use in a direction. In our task,saying "It's the close one" or "It's by the red"did not allow the listener to determine whichreference object the child had in mind. Thepercentage of these nonspecific referencesdecreased dramatically between 4 and 6 yearsand dropped slightly between 6 and 8 years.Nonspecific references also appeared muchmore frequently in directions about the left-right than the front-back dimension at allages. These two findings indicate that chil-dren became increasingly able with age toprovide unambiguous information to their lis-tener.

More generally, the relatively high fre-quency of directions containing references tothe listener suggests that children of all agesgrasped the importance of helping the lis-tener relate his or her position to that of thetarget location. The fact that the 4- and 6-year-olds referred to the listener about twice asoften as they referred to themselves suggeststhat the listener was seen as more than just asalient landmark. Were this not the case, onewould expect equal numbers of references toself and listener, since for half of the front-

back trials the toy was located in a cup closerto the child than the listener, and for the otherhalf the opposite was true. Hence, the higherproportion of references to the listener in-cludes directions such as "It's the farthest onefrom you." Such statements indicate that chil-dren were able to communicate location fromthe listener's perspective rather than merelymarking the location as closer to themselvesor their listener. The results of Experiment 2suggest that the high percentage of referencesto the listener was not just a product of thelistener being close to the table and hence asalient landmark, since references to the lis-tener actually increased when the table wasmoved away from him or her. This is consis-tent with previous work indicating that, by 4years of age, children are able to use theirlistener's perspective in specifying whetheran object is in front of or behind a wall divid-ing the child and the listener (deVilliers &deVilliers, 1974).

Second, children's directions about theleft-right dimension offer insight into howlanguage abilities constrain children's use offrames of reference. Children referred tothemselves and their listener in the majorifyof their directions about the front-back di-mension even when differentiated landmarkswere present This suggests that the low fre-quency of 4- and 6-year-oIds' references tothemselves and their listener in directionsabout the left-right dimension was due totheir inability to use left and right. In con-trast, 8-year-olds referred to themselves andtheir listener relatively often for directionsabout both the front-back and left-right di-mensions. This relatively late developmentalshift toward using self and listener referencesfor the left-right dimension is not surprising,given previous research documenting thatchildren only begin using the terms left andright relationally around 7 or 8 years (Harris,1972).

Finally, the abilify to attend to and selectrelevant spatial information may also accountfor some of the developmental differences ob-served in our task. Children of different agesmay have focused their attention on differentkinds of environmental landmarks. Four-year-olds rarely used landmarks, perhaps becausekeeping track of the hiding location in rela-tion to themselves, their listener, and theother cups occupied their full attentional ca-pacity. Future work may determine whether4-year-olds use landmarks if the task load isreduced, for example, by marking the targetcup. The 8-year-olds' relatively high propor-tion of references to the tape on the table indi-

1542 Child Development

cates that they also focused their attention ona rather narrow area. However, given the 6-year-olds' frequent use of the distal curtains,this tendency of the oldest children to useproximal landmarks most likely reflects theirappreciation of the listener's perspective,rather than an inabilify to use distal land-marks. Other studies in which children's allo-cation of visual attention is directly measuredwould provide empirical evidence for thesehypothesized developmental changes in at-tention.

Task variables can cause children not touse a particular frame of reference for eitherof two reasons. In some cases, task demandsmay make it impossible for children to use agiven frame of reference. For instance, 6-year-olds in the present study may have been un-able to use a self- or other-based frame of ref-erence for directions about left-right arrays. Inother cases, such as 8-year-olds' relatively fre-quent references to the tape, it seems rea-sonable to infer that the task led them tochoose a proximal over a distal frame of refer-ence. Future studies that directly comparereference system use in different spatial taskswould provide a more complete picture of thefactors underlying developmental changes inthe use of frames of reference.

It is worth noting that our task, with itsrequirement not to point, represents one of avariefy of possible communication situations.When the target object is visible to bothspeaker and listener and is not surrounded byother objects, pointing is often all that is re-quired to communicate the object's location.However, when many objects are present (aswas the case with the cup arrays), pointingmust be supplemented with verbal informa-tion. Finally, in some instances the speakerand/or listener cannot see the target objectwhile its location is being communicated. Inthis case pointing is of course not useful and,in addition, the speaker must remember thetarget location and imagine the listener's per-spective relative to that location. The presentreport examined children's abilify to give ver-bal directions when pointing is not useful andwhen it was not necessary to remember thetarget location.

Indicating where things are is an impor-tant, and not well understood, aspect of iden-tifying or referring to objects (Miller & John-son-Laird, 1976, p. 410). The experimentsreported here provide an initial look at howchildren use location to verbally identify atarget object. Many questions remain unan-swered. What governs the choice of a particu-

lar reference object to specify another object'slocation? Why does the choice of referenceobjects change With age? Studies that com-bine methods and theories from the fields ofspatial cognition, referential communication,and language development may provide an-swers to these and other interesting questionsabout spatial reference.

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