introduction: one of the risk factors for cardiovascular disease (cvd) is poor physical fitness....

Midterm Review

Abstract 1

Introduction: One of the risk factors for Cardiovascular Disease (CVD) is poor physical fitness. Socioeconomic status (SES) is often a controlled for variable in physical fitness studies involving adolescence. Other studies that investigate the impact of SES have used only females or analyzed their samples based on racial and ethnic groups. Our study investigated the impact of SES on both males and females with an economic based construct of SES.

Methods: The sample consisted of 954 6th, 7th, and 8th graders from a public Illinois urban middle school. The students participated in the FITNESSGRAM battery of fitness assessments as part of their physical education class. Descriptive statistics were obtained for height, weight, age, and sex. In addition, students were grouped as high or low SES depending on whether or not they qualified for the Federal Free Lunch Program.

Statistics: A multivariate analysis of variance controlled for age and separated by sex was conducted comparing the raw scores from the fitness test for low and high SES students. Odds ratios separated by sex were calculated for the likelihood of not achieving the FITNESSGRAM Healthy Fitness Zone standards for the low SES group.

Results: Females of the low SES group had significantly lower scores on the FITNESSGRAM assessments and were significantly less likely to achieve healthy fitness zone status than the females from the high SES groups. For males, SES was a significant main effect for body composition but not for the other fitness tests conducted.

Conclusion: SES is related to physical fitness in females but not in males. A potential explanation for this is that males are more likely to engage in vigorous leisure time activity regardless of SES than females..

a) study variables SES (independent) Fitness (dependent)

b) Is fitness dependent on SES (for males and females separately)

c) fitness was related to SES (high SES fitter than low), but only for females

d) the study design using design notationN ON O

e) a critique of external validity

From the rubric questions: What is the relationship being studied?▪ Does fitness increase with SES, for males or

females What are the study findings, if any?▪ It did for females, not for males

d) a critique of the external validity

What is the sampling strategy? One school in Illinois SO:

1. It is non-probabilistic2. It is a sample of convenience3. It is a volunteer study (not all will have volunteered)4. But a healthy number, so may have got the vast

majority of the students available – meaning volunteerism may not be that much of a factor.

d) a critique of the external validity To what population/time/setting is the study

being generalized/targeted (either implied or actual)? (Look for author wording confirming the attempted generalization) Population seems to be adolescent males and

females (only restrictions mentioned) No time/setting restrictions – mentioned rural

school but only as identifier of sample, not population


What does the sampling strategy and the actual time and settings of the study imply about the merits of any generalization found above? (Is there a good match, or do you see some mismatches?) One urban school in IL One time only – don’t know whether it was start of fall,

spring, or anything. Lots of factors to mess with here – location in terms or

urban/rural, geographical (part of country), time of study in terms of time of year, and so on.

Need to think of potential to alter relationship of SES with fitness (remembering null result for males, positive for females)


To what extent do you think there is a problem of generalization? In other words, do you think the relationship under investigation, or the results of the study would have potential to change given any of the issues raised? To answer this question, we have to consider:

▪ What moderator variables might have been unwittingly introduced by the sampling strategy

▪ Whether these moderators could interact with the study variables

So what moderators do we have?▪ Urban vs rural location?▪ Time of year?▪ State – east/west, north south?

Could any of these for instance compromise the range of SES found in the study, thereby lessening the likelihood of finding

positive results?

e) a critique of construct validity What are the constructs in the study intended

to measure? State the idea(s) behind the dependent measures State the idea(s) behind the independent

measures Fitness:

Aerobic, anaerobic etc. SES:

Combined measure▪ Financial well-being▪ Social standing▪ Employment type

e) a critique of the construct validity

How is each construct in the study operationalized? State how dependent measures are operationalized State how independent measures are operationalized

Dependent measure: Fitnessgram battery Does include many aspects of physical fitness

Independent measure: “Qualification for Federal free lunch program”. Financially driven factor. But clearly associated with

job status and probably therefore social standing too

e) a critique of the construct validity What are the strengths and/or weaknesses of the

observed operationalizations? Consider the types of validity: face, content, etc. Consider the laundry list of threats. Do so for both constructs!

Fitness gram score Face and content validity...it’s a test developed as an overall

assessment of physical fitness, comprising a battery of tests. Free lunch program

Face and content validity…▪ Directly related to one aspect of SES (financial), indirectly to others (social

status, employment status).

A dichotomous variable though – misses some of the variability of an SES “score” for every participant▪ Basically makes everyone either a 1 or a zero for SES – not great, but not awful

either

e) a critique of the construct validity Is the construct validity issue as described in

previous slide likely to alter the results of the study?

Fitnessgram: No real problems identified.

Free lunch: A dichotomous variable though – misses variability

▪ Could in part explain null result for males.▪ Not relevant for the positive result for females

e) a critique of internal validity What is the study’s design?

N ON O

e) a critique of the internal validity Does the study’s design establish

temporal precedence? No Fitness and SES are assessed at the

same time. There is no manipulation of the “treatment”


covariation of cause and effect? Yes▪ There is variation in SES, and variation in

fitness score, so covariation would be found if it existed. Though variation in SES is not as strong as it could be.

e) a critique of the internal validity

To what extent does the study’s design control for alternate interpretations of the causal relationship? Does it control for: Single group threats?▪ Well, there are two groups…

Multiple group threats?▪ No.

Social interaction threats?▪ No


To what extent is the assertion that the relationship under investigation is causal a reasonable one? This is a very weak design with which to assert

causality. Any number of extraneous variables could be

causing the relationship between SES and fitness for females to pop out. ▪ But thinking of particular candidates would seem to be

a little trickier...

Abstract 1

A large body of research has suggested that focusing on the effects of a movement (external focus) is more effective than focusing on the movement itself (internal focus) for learning and performing motor skills (for reviews see Wulf, 2007; Wulf and Prinz, 2001). Recent research has suggested that age and task complexity may moderate this attentional focus effect. The present study examined the effectiveness of internal and external attentional foci for learning two novel locomotor skills varying in complexity. 48 children (ages 8-10) and 48 adults (ages 19-26) learned to ride a Double Pedalo either with or without stability handles while adopting either an internal or external focus of attention. Participants were instructed to either push their feet (internal focus) or the boards of the Pedalo (external focus) forward to make the Pedalo move. The dependent measure used was time to travel 7 meters. For the simpler task, no attentional focus effects were elicited during either acquisition or retention. With the complex task, there were no significant attentional focus effects in acquisition, but in retention, an external focus of attention resulted in faster times than an internal focus, but only in males. These findings further support the findings of Wulf, Toellner, and Shea (2007), suggesting that a certain degree of instability or error is necessary to elicit external focus benefits. In addition, they corroborate the findings of Wulf, Wächter, & Wortmann (2003) which suggested females and males may be differentially affected by attentional focus instructions.

a) study variables Attentional focus, task complexity, age, gender (ind) Performance (time to travel 7 meters - dependent)

b) Are attentional focus effects moderated by any of the IVs (esp age and task complexity)?

c) Focus effects were dependent on age and task complexity, but only for males.

d) the study design using design notation

- See next slide!

d) the study design using design notation

16 groups (2 focus x 2 complexity x 2 age x 2 gender). Of the 4 factors, two may be randomly assigned (focus, complexity), and two cannot be (age, gender).- hence control of causality could be better for relationships involving the two randomly assigned factors than the other 2.- measured over performance and learning.

e) a critique of external validity

From the rubric questions: What is the relationship being studied?▪ Are attentional focus effects moderated by

any of the IVs (esp age and task complexity)? What are the study findings, if any?▪ Focus effects were dependent on age and

task complexity, but only for males, and only in learning (no effects in performance).


What is the sampling strategy? Looks like school kids from one school, and

students SO:

1. It is non-probabilistic2. It is a sample of convenience3. It is a volunteer study (not all will have volunteered)

d) a critique of the external validity To what population/time/setting is the study

being generalized/targeted (either implied or actual)? (Look for author wording confirming the attempted generalization) Population seems to be children and adults Seems to want to generalize to all motor skills Seems to talk about all levels of performance

and learning


What does the sampling strategy and the actual time and settings of the study imply about the merits of any generalization found above? (Is there a good match, or do you see some mismatches?) One set of school kids from one school, one set of students

from one college (perhaps even one department)▪ No real range of ages within each age group – but that’s a study variable

so will be examined in CV

One dose of practice, one learning interval▪ Would more or less practice make a difference? Would a longer or shorter

learning interval make a difference? (Part of constructs though – so leave for then)

One locomotor task used to generalize to all “novel movements”▪ Surely there could be some task differences?

e) a critique of construct validity What are the constructs in the study intended to

measure? State the idea(s) behind the dependent measures State the idea(s) behind the independent measures

Performance, learning Time to complete the 7m trial Intended to assess performance quality

Age – adult vs. non-adult Attentional focus – movement vs. movement

effect Gender – male/female Task complexity – “error-free” vs errorful

e) a critique of the construct validity

How is each construct in the study operationalized? State how dependent measures are operationalized State how independent measures are operationalized

Dependent measure: Performance – time to complete while practicing Learning – time to complete after some time delay

Independent measure: Attentional focus – asked to adopt a focus Age – junior high vs college age Task complexity – handles vs none Gender – male vs female

e) a critique of the construct validity What are the strengths and/or weaknesses of the

observed operationalizations? Consider the types of validity: face, content, etc. Consider the laundry list of threats. Do so for all constructs!

Dependent measure: time to complete while practicing – outcome only – process? time to complete after some time delay – what delay? Again,

outcome only Independent measure:

asked to adopt a focus – did they? Manipulation check? junior high vs college age – what aged children? Developmental

differences? handles vs none – were their the expected performance differences? Gender – male vs female – why? Purpose of this?

e) a critique of internal validity

What is the study’s design? Two potentially randomly assigned

variables (focus, task complexity) Two definitely non-assigned variables

(age, gender) Two measures – learning,

performance.


temporal precedence? Yes▪ focus manipulation comes before learning

test▪ Absence of pretest might be a problem –

especially if groups not randomly assigned


covariation of cause and effect? Yes▪ Variations in performance and learning with

study variables can be assessed.


To what extent does the study’s design control for alternate interpretations of the causal relationship? Does it control for: Single group threats?▪ Well, there are lots of groups…

Multiple group threats?▪ Partially. Differences across focus conditions and task

conditions could be controlled. Differences across age and gender not so.

Social interaction threats?▪ No control of them – but might not be that much scope

for the threat to operate – only one practice session and one test session.


To what extent is the assertion that the relationship under investigation is causal a reasonable one? This is a reasonable design with which to assert

causality. Need to point out the fact that age and gender

are uncontrolled variables – other factors may be operating that are correlates of these.

introduction: one of the risk factors for cardiovascular disease (cvd) is poor physical fitness....

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