Into To Psych Research 1st Year Notes

INTRO TO PSYCHOLOGICAL RESEARCH

3 Experimental methods

• 1 or 2 tailed

• Confounding variables

4 Validity and Reliability

5 Within and Between subjects

6-8 Experiment types

• True

• Field

• Quasi

• 6 Non-equivalent

• Time series

• Time seires w/ non-equivalent: multiple time series

• 6 Single case

• A-B

• 7 Multiple baseline

• Alternating treatments

• Simultaneous treatments

9 Non-Experimental methods

• Correlations

10-12 Quantitative data

• Questionnaires

• 10 Surveys

• Observations

13 Qualitative data

• Interviews

• Pictures

• Ethnographies

• Data displays

14-15 Descriptive Stats

• Function of stats

• Measures of central tendency and dispersion

• IQR

• SD

• Types of data (Nominal, Ordinal, Interval, Ratio and Cont, Discrete, Dichotomous)

16-18 Tables and Diagrams

• Bar charts, histograms, freq polygons and cum freq polygons

• Distributions

• 16 stem-and-leaf diagrams

• 17 box-and-whisker plots

19 Probability

20 Sign test

21 Wilcoxon Matched Pairs Signed Ranks Test

22 Mann-Whitney U test

23 Parametric tests

24 1 sample T test

2-matched sample T test

25 Independent samples (equal groups)

Independent sample (unequal groups ie pooled variances)

26 Correlation

27 Pearson’s R

28 Spearman’s Rho

29 Chi-Square

30 Chi-Square- 1 sample

31 Chi-Square – 2 categorical variables sample (Contingency X²)

FOR A STAT TEST, WRITE OUT:

Design = IV (state general and then what levels), DV; within-Ps, between-Ps, correlation, freq/chi-sq

Question type = relationship, differences

Data type = qualitative, quantitative

Data type = NOIR, parametric, non-parametric, variances

STANDARD DEVIATION ON CALCULATOR

• Mode

• 3: Stat

• 1: 1-VAR (if 1 set of data) 2: A+BX (if 2 sets of data only use if equal number data)

• Enter values than press AC

• Shift

• 1: STAT

• 4: VAR

• SX/SY for SD of x/y values

• Mode

• 1: Comp for normal mode

Parameter: value of population – no uncertainty

Statistic: value of a sample – has uncertainty stats used to estimate parameter

EXPERIMENTAL METHODS

Involves some manipulation

• True experiments

• Field experiments

• Quasi experiments

• Single case experiments

Hypothesis = prediction of what you expect to find in your study

1 tailed = direction of the rel is fixed in advance ie there is a direction +ve or -ve

2 tailed = direction not specified ie there is a diff in a yet unknown direction

• Allows investigating the casual rel

• Control IV

• Better control of extraneous variables

• Random sampling and random allocation

• Increases internal validity

• At risk of decreasing external and ecological validity

CONFOUNDING VARIABLES

Order effects	Performance in 2nd half may be better due to learning or worse due to tiredness
Participant Bias	Demand charac - tendency of Ps to respond in certain ways because they know they are being observed & believe that they know what the researcher wants
Volunteer Bias	When you seek volunteers, you will get a sample that is not rep of the larger pop
Experimenter Bias	All stages from designing to analysing can be affected. Bias towards a result expected by experimenter

Minimising confounding variables

• Effective randomization

• Single blind = info that could introduce bias or skew the result is withheld from Ps, but the experimenter knows all facts experimenter bias

• Double Blind = attempt to eliminate subjective bias on the part of both experimental subjects and the experimenters. The key that identifies the subjects and which group they belonged to is kept by a third party and not given to the researchers until the study is over.

• Standardised procedures

• Stats

VALIDITY

= measures what it claims to measure. Whether a study scientifically answers the qs it intends to answer

Criterion Validity

• Compares the test with other measures or outcomes already held to be valid

• IQ test validated against academic performance

Content Validity

• Does an IQ questionnaire have items covering all areas of intelligence discussed in literature?

Construct Validity

• Involves the empirical and theoretical support for the interpretation of the construct

• To what extent is an IQ questionnaire actually measuring "intelligence"?

External Validity

• Can results of a study be held to be true for other cases e.g. to different people, places or times?

• Can findings can be validly generalized?

Ecological Validity

• To what extent can research results be applied to real life situations outside of research settings?

• To be ecologically valid, the methods, materials and setting of a study must approximate the real-life situation that is being studied

RELIABILITY

= a test is reliable when it gives consistent results of the same measure

Internal reliability = consistency of a measure within a test (ie all items measuring the same things)

• Split half method (same participant do both halves of the test. If both provide similar results = test has internal reliability)

External reliability = ability to replicate the results and get the same/similar results

• Test-retest method (testing the same participant twice over a period of time on the same test. Similar scores = test has external reliability)

• Inter-rater reliability (comparing the ratings of 2 or more observers)

Ceiling and floor effects

Ceiling effects

• Test is too easy and many Ps score near the top

• Test can’t distinguish between individuals

Floor effects

• Test is too difficult

WITHIN-SUBJECTS (REPEATED MEASURES)

= each P takes part in each level of the IV

• Controls for indiv diff between Ps

• Reduces number of Ps needed – higher consistency

• Allows to follow Ps over time

• Time constraints

• Exp mortality

• Order effects – practice/fatigure effect

• Demand charac

• Solution:

• Randomize order of conditions

• Counterbalancing

Counterbalancing

• Balance effects or order of conditions

• Split each group in half – group 1 does A then B, group 2 does B then A

• Order effects balanced out as they occur equally in both groups

Complete Counterbalancing:

• Requires that all possible condition orders are used

• Eg if 6 levels = 6x5x4x3x2x1=720 orders

Latin Square:

• Ensures that each level of the IV appears equally...

Buy the full version of these notes or essay plans and more in our Intro to Psychological Research (1st year) Notes.