Research methods - Aims, hypotheses & sampling Flashcards
What is the ‘aim’?
What the researcher is trying to achieve
What is a ‘hypothesis’?
A specific prediction of what will be found expressed in a change of variables
What is a null hypothesis?
A statement of what will be found if the experimental/alternative hypothesis is not supported by the result. Used in non-experimental studies.
What is a Non-directional hypothesis?
‘Two-tailed’ , predicts charge, doesn’t specify directions. It is used when there is no previous research. E.g ‘ Alcohol will affect reaction times’. Tends to use words like “effect, change, different”
What is a Directional hypothesis?
‘one-tailed’ predicts the direction of change that is expected. Used when there is previous research. E.g “Alcohol increases reaction time.’
What is sampling?
Selecting a group of participants who take part in a the study
What is a ‘population’?
The broader group that the sample comes from
A sample should always be _____________ of the target population.
Representative, the people in the sample should have similar characteristics
+Allows findings to be generalised to target population
What does Opportunity sampling involve?
Involves accessing participants on the basis of their convenient availability to the researcher. i.e friends, family, classmates. The most common type sampling.
- Very prone to bias, available participants might not be representative
What does Volunteer sampling involve?
Participants select themselves e.g advert in the newspaper article. e.g Zimbardo’s prison experiment
- Attracts certain personalities
What does Systematic sampling involve? Pros and cons?
Applying a regular system to or rule when selecting participants . e.g picking every 50th person that walks along a corridor.
+ Reduces researcher bias
- Some participants might be excluded e.g because they don’t have a phonebook or don’t live in a house
What does stratified sampling involve? Pros and cons?
Selecting participants in such a way to recreate the same proportions of groups that exist in the population. E.g : Selecting people from different ethnic groups to create a sample with the same proportions of groups that exist in the population.
+ Reduces bias by being representative
- Participants must have already been selected using a different sampling techniques before stratification which is time consuming
What does random sampling involve? Pros and cons?
All members of the target population must stand an equal chance of being selected. E.g pulling names out of the hat that has everyone from the target population in.
+ Laws of probability predict that selecting a biassed sample is minimal
- Participants might not want to take part
- Doesn’t guarantee an unbiased sample, could be biased in terms of gender, age etc.
What is event sampling?
Recording an event every time it happens over a period of time. For example, if a researcher was observing a child in a school playground, they may record every example of aggression over a 20-minute period (based on the chosen behavioural categories) . They may also record what else was happening at the same time.
What is time sampling?
Involves recording the most prominent behaviour at some many different points in time. The points in time could be selected randomly or systematically. For example, an observer may observe a child in a school playground once every two minutes, and record what they are doing at that point.
