Lec 2

Question 1

what is an independent variable?

Answer 1

manipulated variable

Question 2

what is an dependent variable?

Answer 2

measured variable

Question 3

what is a confounding variable?

Answer 3

a variable that could influence the outcome of the study

Question 4

which type of hypothesis statement is usually included in a manuscript?

Answer 4

scientific (alternative) hypothesis

Question 5

which types of variables are qualitative data?

Answer 5

nominal
ordinal

Question 6

which types of variables are quantitative data?

Answer 6

interval/ratio

Question 7

T/F: parametric stats can be ran on quantitative variable but NOT qualitative

Answer 7

T

Question 8

which types of studies are descriptive?

Answer 8

surveys
retrospective data (with no comparative or relationship analyses)
normative
qualitative

Question 9

which types of studies are exploratory?

Answer 9

correlative/predictive
methodological

Question 10

which types of studies are experimental?

Answer 10

RCT

Question 11

where do case-control, quasi-experimental, and single subject studies fit in (type)?

Answer 11

between exploratory and experimental

Question 12

when is the alpha level set small?

Answer 12

with the largest risk

Question 13

T/F: the p-value is set in advance.

Answer 13

F

Question 14

what is the alpha level?

Answer 14

pre-set significance level
the point at which you would consider the result highly unlikely
usually 0.05

Question 15

if an alpha level is 0.05, what does this mean?

Answer 15

there is a 5% chance of committing a type 1 error

Question 16

what is a p-value?

Answer 16

the actual probability that the results occurred just because of sampling error

Question 17

what is the worst error to make?

Answer 17

type 1 = saying there is a significance but there is actually not one

Question 18

internal validity issue: history

Answer 18

did something happen pre and post testing to change the results?

Question 19

internal validity issue: maturation

Answer 19

did the participants change over time?
ex: children, disease recovery

Question 20

internal validity issue: attrition/mortality

Answer 20

who dropped out and why?

Question 21

internal validity issue: repeated testing

Answer 21

did repeated testing change outcome?
get good at a test more times its administered

Question 22

internal validity issue: instrumentation

Answer 22

did the measurement tool change?
does the tool need calibration?

Question 23

internal validity issue: regression to the mean

Answer 23

groups with initial extreme scores tend to regress towards the mean

Question 24

internal validity issue: experimental bias

Answer 24

researcher is biased and influences the outcome

Question 25

internal validity issue: selection

Answer 25

did groups differ in key ways? did the sample not represent the population?

Question 26

type 1 error

Answer 26

reject null when shouldn't

Question 27

type 2 error

Answer 27

fail to reject the null when should have usually d/t low power or small sample

Question 28

simple random sample

Answer 28

sampling in which the researcher randomly selects a subset of participants from a population (ex: all TX students have equal chance of selection)

Question 29

systematic sampling

Answer 29

probability sampling method in which a random sample, with a fixed periodic interval, is selected from a larger population (ex: pick every 20th student)

Question 30

stratified sampling

Answer 30

the division of a population into smaller subgroups (ex: pick 10 student from every DPT program)

Question 31

cluster sampling

Answer 31

the sample frame is divided into sections but only certain parts or sections are used (ex: student picked from 3 randomly selected programs)

Question 32

convenience sampling

Answer 32

the members of the sample frame volunteer or self-elect

Question 33

what is the equation for cohen's d?

Answer 33

d=(difference in means)/(pooled std)

Question 34

a ___ cohen's d is better

Answer 34

larger

Question 35

there is ____ variability with a larger effect size

Answer 35

less

Question 36

when effect size goes up, power goes ___

Answer 36

up

Question 37

when number of participants go up, power goes ___

Answer 37

up

Question 38

what is a small effect size?

Answer 38

0.2

Question 39

what is a medium effect size?

Answer 39

0.5

Question 40

what is a large effect size?

Answer 40

0.8