Research Methods Flashcards
Directional Hypothesis. One or two tail?
Explicitly states the direction of difference/relationship
One-tail
Non-Directional Hypothesis. One or two tail?
Does not state the direction of difference/relationship
Two-tail
Independent Variable
Aspect of experiment which is manipulated by the researchers so the effect on the DV can be measured
Dependent Variable
Measured variable, changed caused by changed in IV.
Operationalisation
Clearly defining variables in terms of how they can be measured
Extraneous Variable
Any variable that is not taken into account which impacts the DV and is not controlled
Confounding Variables
Any variable, either than IV, that has an impact on the DV yet we cannot be sure how much it did. Means the source of the DV’s change is can not be truly identified.
What is standardisation?
What are its effects?
Ensuring that all participants have the same experience within the experiment. This is done by making sure the procedure and instructions are identical.
Prevents experimenter bias and limits confounding experiments. Makes it easier to repeat/make reliable
What is the concept of significance?
Just because a difference is found, does not mean that it is significantly different. You have to check that the results are not just due to chance. You can work this out via statistical testing
What are null and alternative hypothesis?
Null: States the opposite of the alternate. Called it because it says it will not.
Alternate: States the expectation of the experiment’s outcome.
What’s opportunity sampling?
Example?
Choosing ppts based on who’s in a certain location. Has to be relevant/appropriate.
Experiment on effects of energy drink using ppts from a gym
What’s random sampling?
When there is no strategy involved, in a school you get a register and randomly choose names.
What’s stratified sampling?
Groups of ppts are selected in proportion to their frequency in target population
What are the 2 types of error?
Type 1: Alternate accepted, Null rejected, yet should be the other way around. A sig. difference does not exist
Type 2: Null accepted, Alternate rejected, yet should be the opposite. A lack of significance is perceived to have been found
What is the concept of significance in psychological research? Or why do we use tests of significance?
Just because a difference is found, does not mean that it is significantly different. You have to check that the results are not just due to chance. You can work this out via statistical testing