Research Methods AS L5 - 8 Flashcards
3 steps of conducting research:
1) Deciding an aim
2) Decide IV and DV + operationalise
3) Decide a hypothesis + operationalise
Aim:
Precise statement about purpose of study + what it intends to find out
Hypothesis:
Precise, testable statement about expected outcome of investigation
Null hypothesis:
IV will have no effect on DV
Alternative/Experimental Hypothesis:
IV will have an effect on DV
Non-directional hypothesis (two-tailed):
Direction of predicted differences between conditions not shown eg. eating chocolate will significantly affect a person’s mood
Directional hypothesis (one-tailed):
Direction of the predicted difference between condition is shown eg. eating chocolate will increase a person’s mood
Target population:
The group who researchers are studying and want to generalise their results to
Why are sampling techniques used?
Obtain a sample of target population to avoid studying entire populations, as it is too long and expensive
What should a sample aim to be like?
- Representative of population
- Same characteristic as population
Random sampling:
- Every member of target population has an equal chance of being selected
- Use a bias-free method to select a sample
Strengths and weaknesses of random sampling:
+ If target population is large and sample is large, sample is likely to be representative
+ No researcher bias as sample has been chosen by chance
- Difficult to get full details of target population
- Not all members of target pop will be willing to participate/be available, making sample unreliable and reducing the sample size
Systematic sampling:
Participants are selected by taking every nth person from a list of the total pop
Strengths and weaknesses of systematic sampling:
+ Much simpler than random sampling as it only requires a list of target pop
- Process of selection can interact with a hidden periodic trait within pop due to coincidence
- Not all members of target pop will be willing to participate/be available, making sample unreliable and reducing the sample size
Stratified sampling:
- Classifying pop into categories and randomly choosing a sample that consists of participants from each category in the same proportion as they are in the pop
- Divided into strata in terms of characteristics
Strengths and weaknesses of stratified sampling:
+ All grps within pop are included, therefore it is representative
- Time-consuming
- Hard if you do not have details of everyone in stratified sample
Opportunity sampling (Convenience sampling):
- Selecting participants who are readily available and willing to participate
- Possibly easy access to a group of people they know well
Strengths and weaknesses of opportunity sampling:
+ Easiest and most practical method for large samples in comparison to stratified sampling
- High chance sample will not be representative
- Sometimes people feel obliged to participate in research (especially if researcher is known to them), which is possibly unethical
Volunteer sampling:
- Volunteering to participate in a study
- Researcher usually advertises for people to participate thru leaflets, posters, radio or TV broadcasts
Strengths and weaknesses of volunteer sampling:
+ Time and effort is saved as the researcher only needs to wait for pps
- Certain type of person tends to volunteer eg. Someone who is interested about the topic therefore it is possible the sample is unrepresentative
In a pilot study, what is it important to check when using self-report measures?
- Understanding of questions
- Closed questions still offered suitable options
- Whether open questions are needed to elicit unpredictable responses
- Appropriateness of reporting methods
In a pilot study, what is it important to check when using observations?
- Operationalised definitions of behavioural categories are agreeed by observers
- Inter-observer reliability (do researchers need to practise observing behaviours?)
- That behavioural categories include all important behaviours
- Behavioural categories don’t overlap
- Whether pps are affected by observers (should it be covert?)
Which two effects should be checked in a pilot study?
- Floor effect = None of the pps can complete the task as it is too hard
- Ceiling effect = Task is so easy pps can virtually achieve full marks
Experimental designs:
- How pps are organised w/in the experiment
3 types of experimental designs:
1) Independent grps
2) Repeated measures
3) Matched pairs