ANOVAs + Stats

Question 1

One-way anova

Answer 1

used to determine whether there are any statistically significant differences between the means of three or more independent groups

Question 2

Repeated measures ANOVA

Answer 2

used to determined if there are significant differences within the same group over time

Question 3

MANOVA

Answer 3

ANOVA with several dependent variables

Question 4

ANCOVA

Answer 4

used when there may be a confounding or interacting variable in your ANOVA

Question 5

Covariate

Answer 5

another variable that may be affecting resutls

Question 6

Two-Way ANOVA

Answer 6

studying two or more independent variables at the same time, each with at least two levels/time-points

Question 7

Mixed Effects ANOVA

Answer 7

combination of a one-way ANOVA and a repeated measures ANOVA

looking at both a between-subjects and within subjects effect

Question 8

Main Effect

Answer 8

looking just at the effect of 1 independent variable on 1 dependent variable

Question 9

Interaction effect

Answer 9

looking at whether the effect of one variable depends on the effect of another variable

Question 10

False Positive

Answer 10

Type 1 Error
Reporting an effect when there is actually no effect
Chance of committing a Type 1 error = alpha

reducing type 1 error means reducing alpha level

Question 11

False Negatives

Answer 11

Type 2 Error
reporting no effect when there is an effect
chance of committing type 2 error = beta

reducing type 2 error = increasing sample size

Question 12

Power

Answer 12

equivalent to 1 - Type 2 error
increasing sample size increases the power of your study

.8 power is very good

Question 13

Power analysis

Answer 13

generally performed before the study

uses sample means and SDs to estimate sample size
more power is needed to detect small differences, more participants increases power

Question 14

Effect Size

Answer 14

quantitative measure of the magnitude of the experimental effect

a statistically significant result can have a small effect, or vice versa

Question 15

Minimal Clinically Important Difference

Answer 15

smallest change in a treatment outcome that a patient would identify as important

subjective measurement

Question 16

Reliability

Answer 16

extend to which a measured value can be obtained consistently during repeated assessment

Question 17

Validity

Answer 17

the extent to which a test measures what it is intended to measure, center of bullseye

Question 18

Sources of Measurement error

Answer 18

Individual
Measurement instrument
characteristic being measured is variable

Question 19

Test-Retest Reliability

Answer 19

consistency of results when you repeat the same test on teh same sample at a different point in time

Question 20

Intra-Rater Reliability

Answer 20

consistency of the data recorded by one rater over several trials

Question 21

Inter-rater reliability

Answer 21

consistency used to evaluate the extent to which different judges agree in their assessment decisions

Question 22

Minimal Detectable Change

Answer 22

amount of change in a variable that must be achieved before we are confident that the change is not simply due to measurement error

Question 23

Number needed to treat

Answer 23

metric used to calculate the effectiveness of an intervention. Smaller for longer duration studies

prevention-focused: # of pts that would need to be treated to prevent 1 adverse outcome

improvement focused: $ of pts that would need to be treated to achieve 1 beneficial outcome

if NNT = 1, every pt benefits from tx

Question 24

Number needed to harm

Answer 24

used to calculate the chance of harm for an intervention

larger NNH means pt is less likely experience an adverse event