experimental methods Flashcards
what is the aim of the study?
purpose of study
what is the hypothesis?
• prediction of results
• precise, testable statement
• state relationship between the variables
- independent (refers to both variables)
- dependent (what you measure)
what are types of hypothesis?
1) null hypothesis:
2) alternate hypothesis:
what are the types of alternate hypothesis?
1) directional/one tailed: findings suggest outcome and state the direction eg which group will better?
2) non directional/two tailed: no previous research/findings contradict and state there will be a difference between groups/conditions
what are variables?
anything that can change within an investigation
1) independent variables (IV): things that are manipulated or changed by the psychologist
2) dependent variables (DV): the variables that is measured by the psychologist
how to test level of IV?
to test the effect of the IV we must have different conditions
Conditions= different levels of IV
what are the types of variables?
1) experimental condition: where the IV has been changed in some way
2) control condition: where the IV has not been applied or changed baseline
- to make a clear and testable hypothesis it must be operationalised
- clearly defining variables in terms of how they can be measured
what are the control of variables?
Extraneous variables (EV)
- affects DV if not controlled
- a nuisance variables
what are types of EV?
1) situational
2) participants
3) experimental/investigator affects
4) damand characteristics
what are the situational EV?
situational- aspects of the environment that affects p’s behaviour
eg: location, audience, clear task, time of day/week
what are the participants EV?
participants- refers to the ways in which each p’s varies from the other and how they could be effective the results eg: personality, age, mental health, IQ, gender
what are the experimental/investigator effects EV?
anything the investigator does that has an impact on the participants performance other than what was intended eg personality, non verbal, leading q’s
what are the demand characteristic EV?
P’s have figured out the aim of experimenter, so they change their behaviours
what do the types of EV result in?
1) Please U effect- go along with task
2) Screw U effect- sabotage
what is the experimental method?
- most used method of investigation
- conducted in a lab or any other setting that is unnatural
what is a null hypothesis?
null hypothesis:
- no difference/relationship
- a statements that predicts there will be no effect on the independent variable on the dependent
what is an alternate hypothesis?
alternate hypothesis:
- difference
- what you expect to happen
- a predictions that states what the effects of the independent will have on dependent variables
- directional/non directional
what are confounding variables?
• EV ‘s that change systematically with the IV
• therefore, if the experiment does accidentally include CVs then the experimenter cannot be sure whether the results are the product of the IV or the CV
• impacts the internal validity- accuracy of research
what is controlling variables?
• randomisation
• standardisation
what is randomisation for controlling variables?
• an approach to minimise the effects of EV/CVs
• randomisation is the use of chance in order to control for the effects of bias when designing materials and deciding on condition’s
how is randomisation done?
• randomly select p’s
• randomly allocate to conditions
• randomise q’s in questionnaire
what is standardisation?
• the process in which procedures used in research are kept the same
• to keep all elements of a procedures identical
• the same directions must be read to each student the same question must be given
• to maintain uniformity, some procedures are quiet distraction free environment , precise reading
