Experimental Methods Sept 13 & 14

Objective: Students will be able to explain and evaluate the research methods used in psychology.

Agenda:

1. CBM

2. Reading Check

3. Finish Approaches notes

4. Research Methods notes

5. HW: Research methods chart, essay

Reading Quiz

1. The belief that after an outcome of an event that one could have predicted that particular outcome.

2. Testable prediction usually implied by a theory.

3. Fair representation of a population because everyone has an equal chance to participate.

4. The two elements in an experiment – one is the part being manipulated, while the other is being measured. (Must be in the correct order)

5. Clear statement of procedures which allows the process to be replicated.

Basic Ideas

Goal : Describe, predict, control & explain behaviors

Theory Hypothesis Variables Sampling

Naturalistic Observation

Watch ONLY Used if other methods would be

misleading Large amounts of data Problems:

Change if known being observed See what expect

Case Studies

Individuals/small groups Interviews, transcripts, tests Neuropsychology

Uses:-Raw material-Particular people-Testing ground

Limitations:-Limited evidence-Not representative

Surveys

Uses: Large amounts of

data

Limitations: Validity

Wording Honesty

Distortion

Experimental Method

Controlled by

researcher Independent

variable Item being

manipulated Dependent variable

Item being measured and affected

Control group Receives no

treatment

Experimental group Receives treatment

Operational Definition – define exact steps/methods used in research

Experimental Method cont’d

Confounding variable Any factor that

affects the dependent variable in addition to or instead of the independent variable

Random variable Uncontrolled/

uncontrollable factors Reliability Validity

Experimenter bias Unintentional effect

that researcher may have on results

Placebo effect No benefit but helps

because believe it will

Double blind design No one knows who

gets what

Ex Post Facto

Manipulation has already occurred Use comparison groups Use groups that are in tact Explores possible causes and effects Focuses first on the effect, then

attempts todetermine what caused the observed effect

Statistics

Measures of central tendency – typical scores Mean Median Mode

Measures of variability Range Standard deviation

Calculate the mean, median & mode for the following numbers4, 3, 7, 2, 5, 4, 4, 8

Correlation

Correlation coefficient

Positive Correlation Negative

Correlation

Correlation v. Causality

 experimen

tcase study

naturalistic observation

surveyCorrelational

studies

description

       

weakness        

strength        

scenario in which

this method could be

used

       

EssayPsychologists use a variety of research methods to study

behavior. Three of the main research methods used are Case study Correlational Study, and ExperimentA. Discuss one advantage of each research method mentioned above.B. Discuss one disadvantage of each research method mentioned

above.

Pretend you are a psychologist who will use each of the three research methods – case study, correlational study, and experiement – to determine the effect of taking vitamin J on improving memory.

C. For each method listed above, explain a key characteristic of the basic approach you could use to reach a scientific conclusion about the relationship between taking vitamin J and improving memory. You need not design a complete study.