Research and Evidence Based Practice

Question 1

What 3 components make up evidence based practice?

Answer 1

Research evidence
Clinical expertise
Patient values

Question 2

Explain correlation coefficients (r) ranging from -1.00 to +1.00.

Answer 2

R near +1.00 = positively correlated variables
R near 0.00 = variable not related
R near -1.00 = negatively correlated variables

Question 3

What is a nominal scale? Provide an example.

Answer 3

Classifies variables or scores into two or more mutually exclusive categories based on a common set of characteristics

Example: male or female; tall or short

Question 4

What is an ordinal scale? Provide an example.

Answer 4

Classifies and ranks variables or scores in terms of the degree to which they possess common characteristics.

Intervals between ranks are NOT equal

Example: MMT

Question 5

What is an interval scale? Provide an example.

Answer 5

Classifies and ranks variables or scores based on predetermined equal intervals. Does not have a true zero point.

Example: Temperature; IQ scale ranging from 0-200

Question 6

What is a ratio scale? Provide an example.

Answer 6

Classifies and ranks variables or scores based on intervals and a true zero point.

Example: goniometry, scales for height, weight or force

Question 7

A _____ scale is the least precise level of measurement, while a _____ scale is the most precise level of measurement.

Answer 7

Nominal = least precise 
Ratio = most precise

Question 8

What is the difference between a random versus stratified sample?

Answer 8

Random = all individuals in a population have an equal chance of being chosen for a study

Stratified = individuals are selected from a population from identified subgroups based on some predetermined characteristic (i.e. by height, weight or gender)

Question 9

What is validity?

Answer 9

Refers to the extent to which a test, instrument or procedure accurately measures what it is supposed to measure

Question 10

What is the difference between internal and external validity?

Answer 10

Internal = the degree to which the observed differences on the dependent variable are the direct result of manipulation of the independent variable and not some other variable

External validity = the degree to which the results are generalized to individuals or environmental settings outside of the experimental study

Question 11

What is the Hawthorne effect?

Answer 11

The subject’s knowledge of participation in an experiment influences the results of a study

Question 12

What is reliability?

Answer 12

The degree to which an instrument measures a phenomenon accurately, dependably, time after time, and without variation

Question 13

What is the difference between interrater and intrarater reliability?

Answer 13

Interrater = the degree to which two or more dependent raters can obtain the same rating for a given variable

Intrarater = the degree to which one rather can obtain the same rating for a given variable on multiple measurement trials

Question 14

What is the difference between a subjective versus objective tests?

Answer 14

Subjective = results differ based on who is grading the test

Objective = results will always be the same regardless of who grades the test

Question 15

What is the difference between sensitivity and specificity?

Answer 15

Sensitivity (SNout) = a test’s ability to correctly identify the proportion of individuals who truly have a disease or condition (true positive)

Specificity (SPin) = a test’s ability to correctly identity the proportions of individuals who do not have a disease or condition (true negative)

Question 16

What is the purpose of a t-test?

Answer 16

Used to determine if there is a difference between two groups

Question 17

What is the purpose of an analysis of variance (ANOVA)? How is an ANCOVA different from an ANOVA?

Answer 17

Used to determine whether there are differences among three or more groups.

ANCOVA (analysis of variables) = also controls for the effects of intervening variables as well as assess if there are differences among 3 or more groups

Question 18

What is the purpose of a chi square test?

Answer 18

Tells the researchers whether the observed pattern, trait or distribution is different than what would have been expected by chance alone

Question 19

What is the effect size?

Answer 19

Magnitude of difference between groups

Question 20

What is a p value?

Answer 20

An estimation of true differences, not due to chance
Most commonly set at 0.05 or 0.01

P avalue tells us whether an effect exists, but does not share the size of the effect

Question 21

Describe the reliability values for positive correlations (r).

Answer 21

Good reliability > 0.75
Moderate reliable = 0.5-0.75
Poor reliability < 0.5

Question 22

What is a confidence interval?

Answer 22

A range of values so defined that there is a specified (usually 95%) probability that the value of a parameter lies within it

Question 23

______ are more statistically powerful than sensitivity and specificity.

Answer 23

Likelihood ratios

Very high likelihood ratios (10 or more) rule in a diagnosis.
Ratios or 0.1 or less rule out a diagnosis.
Anything in between is inconclusive.