New Terms

Question 1

Snowball Sampling

Answer 1

Participants recruit others; + access difficult to locate groups; - not a good cross-section of population.

Question 2

Online Experiments

Answer 2

assess participants via internet/social media; + assess large groups, cost effective, diverse, quicker analysis; - difficult to deal with ethical issues, limited methods used.

Question 3

Systematic Sampling

Answer 3

Every nth number of the population; + no researcher bias; - may not be representative.

Question 4

Inter-rater Reliability

Answer 4

Extent to which 2 observers agree. General rule is that if there is 80% agreement, then there is inter-observer reliability.

Question 5

Test-retest Reliability

Answer 5

Assess external reliability. Participants do test, then sometime later when they have forgotten, they do the test again and the responses are compared.

Question 6

Split-half Reliability

Answer 6

Assess internal reliability. Participants are given a test, the responses are split and compared.

Question 7

Concurrent Validity

Answer 7

Way of establishing external validity by comparing an existing test or questionnaire to one you are interested in.

Question 8

Predictive Validity

Answer 8

Correlating the results of the test with some other examples of the behaviour that is being tested.

Question 9

Face Validity

Answer 9

A form of external validity - the extent to which test items look like what the test claims to measure.

Question 10

Content Validity

Answer 10

Aims to show that the content , like questions on the test, represent the area of interest (internal validity).

Question 11

Construct Validity

Answer 11

The extent to which performance on the test measures an identified underlying construct (internal validity).

Question 12

Frequency Table

Answer 12

Used to display raw data that Is easy to understand and interpret.

Question 13

Bar Charts

Answer 13

Used with interval and ratio data. Used to display data or information that changes continuously over time and allow us to see overall trends such as an increase or decrease in data over time.

Question 14

Histograms

Answer 14

Use continuous rather than discrete data in a bar chart. The variable in the horizontal is a scale of something such as length or mass. used with interval data.

Question 15

Pie Charts

Answer 15

Shows differences in frequencies and percentages amongst categories of a nominal or ordinal data.

Question 16

Scatter Diagrams

Answer 16

Used to display data when study is correlational.

Question 17

EEG

Answer 17

Electrodes placed on scalp and electrical activity in different areas can be recorded.
E.g. Dement Kleitman - detected different stages of sleep.

Question 18

CAT

Answer 18

Takes a series of x-rays to for 2 or 3 dimensional pictures. Usually a dye is injected as a contrast and the patient is place in the CAT machine.

Question 19

MRI

Answer 19

Use of magnetic field that causes the brain to emit radio waves, a detector reads these and uses them to map the structure of the brain.

Question 20

PET

Answer 20

Slightly radioactive glucose given to patient. Most active parts of the brain use glucose and radiation detectors “see” this area, building up a picture of activity in the brain.

Question 21

Longitudinal Studies

Answer 21

Research conducted over long periods of time to observe long term effects. Case studies are often longitudinal. Often used by developmental psychologists.

Question 22

Cross-sectional Studies

Answer 22

One group of a younger age are compared to another groups of an older age at the same point in time to investigate effects of age on behaviour.

Question 23

Normal Distributions

Answer 23

Classic bell shaped curve.
Features: mean, median, mode in exact mid point.
Distribution symmetrical at mid point.
Dispersion of scores either side of the mid point is consistent and can be expressed in standard deviation.

Question 24

Left Skew/Negative

Answer 24

Some population scores are distributed equally around the mean.
E.g. Easy test - mostly high scores - negative skew.

Question 25

Right Skew/Positive

Answer 25

Some population scores not equally distributed.
On scale, if most on lower end, positive skew.
The few extreme scores have a strong effect on mean- - mean always higher than median and mode in positive skew.