Lecture 2

Question 1

What is the manipulated variable called?

Answer 1

Independent variable

Question 2

What is the measured variable called

Answer 2

dependent variable

Question 3

What is a confounding variable

Answer 3

additional variable that can influence the dependent variable besides the independent variable

Question 4

Quantitative research

Answer 4

Uses numbers

Independent variable is manipulated

considered “traditional method”

cause/effect

More precise

Question 5

Qualitative research

Answer 5

Test theories using language

focus on broad understanding of complex phenomenon

no manipulation of Independent variable

Purposeful subject selection, not random

Question 6

Single subject research

Answer 6

One or few participants measured many different times to understand progression

Question 7

What is usually in a manuscript: Null OR alternative hypothesis?

Answer 7

Alternative hypothesis

Question 8

Nominal scale?

Answer 8

Categories with no defined order

Question 9

Ordinal scale

Answer 9

Categories with non-numeric order

Question 10

Interval scale

Answer 10

Numeric scale without a true 0

Question 11

ratio scale

Answer 11

numeric scale with a 0

Question 12

Easy - Medium - Difficult

What kind of scale is this?

Answer 12

Ordinal Scale

Question 13

Male or Female

What kind of scale is this?

Answer 13

Nominal

Question 14

T or F: You run a T test for qualitative data

Answer 14

F

Question 15

Descriptive research study

Answer 15

Describe data without statistical analysis

example: collect “normative data” that is used for comparison later on

Can include qualitative research like interviews

Question 16

What is the purpose of exploratory research studies

Answer 16

Finds relationships between variables

example: case control (quasi-experimental AKA Cohort)

Question 17

What is an experimental study

Answer 17

Demostrate cause and effect

must have randomization

note: one study cannot prove anything, it takes many

Question 18

Quasi-experimental studies are also known as

Answer 18

Cohort studies

Question 19

What is alpha level?

Answer 19

Significance level that is set in advance

it is the point you’d consider the result unlikely (happened by chance)

Usually 0.05, for research with major risk it is typically lower

Question 20

What is P value

Answer 20

The actual probability that the research results occured due to chance

Question 21

What do you do if the P value is greater than the alpha value

Answer 21

Reject the experimental hypothesis

null hypothesis is true

Question 22

What is research validity

Answer 22

Extent to which the research is useful/believable

Question 23

How can HISTORY influence internal validity

Answer 23

Something happened pre or post-test to change the results

example: participants became friends

Question 24

How can Maturation affect internal validity

Answer 24

Patients naturally got better or grew up from being children

Question 25

How can attrition/mortality affect internal validity

Answer 25

People left the study prematurely

Question 26

How can repeated testing affect internal validity

Answer 26

People got better at taking the test

Question 27

How can instrumentation affect internal validity

Answer 27

uncalibrated or different equipment used to measure

Question 28

How can regression to the mean affect internal validity

Answer 28

Very different groups became more average overtime

Question 29

How can experimenter bias affect internal validity

Answer 29

researcher is bias and wants specific outcome

Question 30

How can selection influence internal validity

Answer 30

population selected does not represent the actual population

Question 31

What is construct validity

Answer 31

Does an instrument actually measure what it claims to measure example: Can you use range of motion as a measure of "Functional capability?"

Question 32

What is external validity?

Answer 32

Can the results be generalized onto the population it's intending to represent?

Question 33

What is statistical conclusion validity

Answer 33

Does the test have enough power? Sample size? Excessive variability of dependent variable? Were there errors made in calculation or the conclusion? Example: type 1 or type 2 error

Question 34

Type 1 error

Answer 34

Reject the null hypothesis when you shouldnt have normal probability is 5/100 (remember the 0.05 alpha level)

Question 35

type 2 error

Answer 35

Fail to reject the null hypothesis AKA claim the study is not valid when it is

Question 36

Simple random sample

Answer 36

everyone has equal chance of being selected

Question 37

Systematic sampling

Answer 37

Selection of participants using certain order

Question 38

Stratified sample

Answer 38

The sampling frame is divided into parts (example: I Want 10 students from every program)

Question 39

Cluster Sampling

Answer 39

Sample frame is divided, but we will only use specific parts example: I only want 10 students from 3/8 of the availible programs

Question 40

Convenience sampling

Answer 40

Members self-volunteer

Question 41

Sampling error

Answer 41

Discrepancy between sample statistic and the population parameter (your surveys sample vs who you're trying to represent with the study)

Question 42

What does Cohen's D measure

Answer 42

Effect size

Question 43

How do you find Cohens D?

Answer 43

(Mean 1 - Mean 2) / (avg standard deviation) Difference between 2 means divided by the average standard deviation

Question 44

A larger cohen's D means what

Answer 44

Larger effect size

Question 45

Cohen's D amounts 0.2 0.5 0.8

Answer 45

0.2 - small 0.5 - medium 0.8 - large

Question 46

How do you find Cohen's D: Group A mean: 1.235 SD: 0.24 Group B mean 0.942 SD: 0.35

Answer 46

(1.235 - 0.942) / ((0.24+0.35)/2)