Public information symbols : a comparison of ISO testing prcedu

res

Author: Christof Brugger

Repot: Yang Kun, Ou

Introduction

• Technical committee 145 of the ISO has been working on improving the introduction of comprehensible public information sybmols since the beginning of the 1970s (ISO 致力改善 )

Introduction

• Responses from subsequent comprehension /recognition testing in four or more countries are categorized by three independently working judges using the seven categories

Response categories for the evaluation

• Category Criterion– 1 Correct understanding of the symbol is certain

– 2 Correct understand of the symbol is likely

– 3 Correct understand of the symbol is marginally likely

– 4 The response is opposite to the intended meaning

– 5 The response is wrong

– 6 The response given is Don’t Know

– 7 No response is given

Appropriateness ranking test

• Respondents– 50 位受測者 (28 male, 22 female)– 15-78 years (M=34)– The experiments were collected data in the Vi

enna, Austria

Method

• Stimuli– symbol were used stimuli for figure 1– Displayed in black and white on an A7-sized c

ard– In center position with a size of 30mmx30mm

Figure 1: Test symbols

Procedure

• A respondent had to rank, successively of the symbol

• The respondent was asked to read the information card

• Spread all the test cards on a table, and to rank-order the variants according to their appropriateness for the particular referent

Scoring

• The median ranking positions in accordance with ISO 9186 were determined for each symbol

• The median values for each referent were transformed into normalized values (100 is best, and 0 is worst)

Appropriateness class assignment test

• Respondents– 67 位受測者 (34 men, and 33 women)– Average age was 32 years

• Stimuli– 與實驗一相同

Procedure

• As in the appropriateness ranking test all cards for one referent were handed over in a stack with the information card on top ( 疊在手上一張一張問 )

• Respondent one of three classes of appropriateness– Highly appropriate– Slightly appropriate– Not appropriate

Scoring

• According to the proposed method, the frequency of class 1 assignments of a variant (highly appropriate) was used as a measure of its appropriateness

Comprehensibility estimation

• Respondents– 51 位受測者 (22 man, and 29 women)– Average age was 33 years

• Stimuli– Referent was 30mmx30mm in black and white,

arranged in a circle on an A4-sized page

Procedure

• The respondents were instructed to read the information in the centre of each page

• Write next to each symbol and estimation of the percentage of the Austrian population that, in their opinion, would understand its meaning

• Scoring– The mean estimation score was computed for each

symbol

Comprehension text

• Respondents– 311 位受測者 (198 man, and 113 women)

• Stimuli– Size of 30mmx30mm were made on A7-sized pages– One symbol per page– First page used for registering age and sex– Second page was instruction sheet– Third page showed an example

Procedure

• Write below each symbol his or her interpretation of the meaning

• No information about context

• Respondent never had to give the meaning for more than one symbol variant for a specific referent

scoring

• As specified by ISO 9186 each answer was assigned to one of seven possible categories by three independently working judges

• In the cases where the judges did not agree on one single category, the category assigned by the majority of the judges was chosen

scoring

• The comprehension score is derived from the percentages of responses in categories 1 to 3

Results and discussion

• Use Friedman tests and subseqently to Wilcoxon signed-rank tests

• Significant differences were found within all sets (P<0.01)

• The relation between the two rating tasks and the ranking task be colser (r=0.82) than the relation between the rating tasks and the ranking task (r=0.49, 0.70)

Results and discussion

• Correlations of the rating scores with comprehension scores were highly significant with r=0.51 for appropriateness class assignment means and r=0.76 for comprehensibility estimation

Conclusions

• ISO has therefore decided that this test will not be a part of the future standard testing procedure and to use the comprehensibility estimation test instead