Midterm review

Abstract 1DV

IV

Abstract one

• Relationship… Cardiovascular fitness and time of instruction

• Outcomes Increased fitness gain with increased instruction time.

Not found – only 90 min group improved significantly.• Design

N O X1 ON O X2 ON O X3 ON O X4 O

Abstract one - EV• Sampling strategy – non-probability convenience sampling. • Intended generalization

Population - children. Time – school year (s) Setting – school PE classes, timing of pre and post tests.

• Mismatch? Lots to talk about – one school? Range of schools? Ages of kids – only one grade covered. Lots of potential moderators.

• Most obviously an issue with the PE practice within these classes being typical of PE everywhere else and at all other ages. 8-9 year olds may well play outside of PE, and so might not need as much daily PE. (all PA outside PE is an uncontrolled threat applying equally to all groups)

• Timing – pretest comes after summer – could be an issue of being sedentary after summer break. Falsely low? Hence all groups improving.

• Timing – if weather conditions, or indeed any conditions, differ in pre- and post tests, then scores can differ.

• Maturation – of course all groups got better – they’ve matured.

Abstract one - CV• Cardiovascular fitness – one mile run

Has face validity Content - best fitness measure? Reliability? Sensitivity?

• Instruction time – 4 days, 3 days, two days, one day. All over an entire year of PE. Instruction time not equal across daily measures Again has face validity. Content - No detail on goals of PE curriculum for this age group.

Could lead to variation across levels of the IV due to differing curricula, fit of curricula to fitness, rather than to amount of time in PE.

No baseline measure (zero PE)

Abstract one - IV

• Non-equivalent groups design• All multiple group threats relevant• Design allows for temporal precedence and covariation• Problem is in lack of control for alternative causes.

Same schools, different schools? Given that start may be low due to summer break, gains thereafter could be due to anything that differs across classes: Time of instruction, type of instruction, general activity level in

school (if different schools), general activity level in locality (if different schools), instructor, differences in recess time in school…and so on.

Abstract two

Abstract two

• Relationship… Proprioceptive training for the ankle and postural sway

• Outcomes Expected – proprioceptive gp gains in stability. Null – only a difference between 1- and 2-leg balance

tasks. No effect of proprioception program. No pre to post test difference.

• DesignR Oo, Oc Oo, OcR Oo, Oc X Oo, Oc

Abstract two - EV• Sampling strategy – no information. At a guess non-probability

convenience sample, and volunteers. • Intended generalization

Population – “healthy” individuals. All ages, genders, ethnicities, SES, etc…

Time – unclear Setting – testing in lab, training at home.

• Mismatch? Well, sample matches intended population, but very broadly defined. At

a guess volunteers were students. Both older and younger participants might differ.

Response to training almost guaranteed to be a minimum in this sample.

Abstract two - CV• Postural sway

AMTI force plate. One legged stance. Three ten second trials. Presumably looking at stability of center of mass. Face validity good. Duration sufficient? Difficult enough?

• 4 week training program One and two leg exercises. All on floor. Again has face validity. Location? Home – no supervision. May not have complied/adhered. Duration? 4 weeks enough? Exercises demanding enough? Could have

used a flat surface, shoes off, padded surface, stability ball...

Abstract two - IV

• Two group randomized pre-post design• 12 p/gp enough for random assignment?• Multiple group threats controlled except selection-

mortality. No mention of drop out.• Design allows for temporal precedence and

covariation• Possible social threats, though the likelihood of

these emerging seems small.• Experimenter bias not suggested by null results.