Analyzing Data from Independent Groups: Continuous and Ordinal Measures

Question 1

Most common experimental design in psychological research.

Answer 1

Independent group designs

Question 2

Independent group designs

Used for comparing ______ groups which are independent of one another – meaning there are different people in each group.

Answer 2

two or more

Question 3

Can be used for _____ and ________ designs.

Answer 3

true and quasi-experimental

Question 4

people are not assigned to conditions, as they already belong to different groups.

E.g., Males and Females, Normal and Abnormal etc.

Answer 4

Quasi-experimental designs

Question 5

Independent groups designs – three different kinds of ______ can be used.

Answer 5

dependent variable

Question 6

Avoids the problems inherent in repeated measures designs;
1.
2.
3.

Answer 6

practice effects
sensitization
carry-over effects

Question 7

Disadvantage – more people, difficulty of matching controlled group with ______

Answer 7

experimental group

Question 8

Statistical Tests for Independent Groups Data

Answer 8

1. the independent groups t-test
2. the mann-whitney test
3. the chi-square test

Question 9

also called the wilcoxon mann whitney test

Answer 9

the mann-whitney test

Question 10

Use of test depends on data being tested.

Answer 10

the chi-square test

Question 11

also known as the between subjects t-test or the two samples t-test.

Answer 11

the chi-test

Question 12

Two (or Three) Assumptions about the Data

Answer 12

• Continuous/interval scale
• Data within each group is normally distributed. We need to make sure that the data are approximately normally distributed within each group.
• The SD of the two groups are equal.

Question 13

there are actually two kinds of t-test, one makes the assumption of homogeneity of variance,__________ and one does not.

Answer 13

assumption of homogeneity of variance

Question 14

The one which makes the assumption is _____

Answer 14

easier.

Question 15

Sample size must be above some value, such as 6, for the t-test to be valid

Answer 15

dispelling myths

Question 16

Sample sizes must be balanced, or similar.

Answer 16

dispelling myths

Question 17

To look at the overall distribution of data to determine whether the data are appropriate for an_______

Answer 17

independent samples t-test

Question 18

distribution of two (or more) groups can be shown for the same amount of space.

Answer 18

Box and whisker plot

Question 19

in calculation of the independent groups t-test use _______ instead of histogram

Answer 19

box and whisker plot