Research Methods - Scientific Processes (5-8) Flashcards
Discuss aims
A precise statement about the purpose of the study, and what it intends to find out
It should include what is being studied, and what the study is trying to achieve
E.g.
“An investigation into the effect that eating chocolate has on a person’s mood”
Describe operationalisation of variables
Decide upon the independent variable (IV) and dependent variable (DV) and operationalise them
Operationalisation is defining the variables in such a way, as to make them easy to measure
E.g.
In a study into the effects of chocolate on mood the operationalised IV would be the type of chocolate and how much is consumed.
The operationalised DV could be participants rating of their mood on a scale from 1-10. (10 being very happy and 0 very unhappy).
Describe a hypothesis
What must be done to it?
Talk abt changes in DV
A hypothesis is a precise, testable statement about the expected outcome of an investigation.
Differences in the DV resulting from manipulation of the IV are known as significant differences if it has been statistically shown that the differences are highly unlikely to be due to chance.
The hypothesis should also be operationalised. For example, ‘eating 250g of milk chocolate will mean that participants are significantly more likely to score between 7-10 on a mood scale from 1-10 than if they have not consumed chocolate.
State and explain the kind of hypothesis
Null Hypothesis: This states that the IV will have no effect on the dependent variable (e.g. ‘eating chocolate will have no significant effect on a person’s mood’).
Alternative/Experimental Hypothesis: This predicts that the IV will have an effect on the DV, e.g. Chocolate will have an effect on mood
The alternative hypothesis falls into one of two categories.
Non-Directional Hypothesis: Two tailed. This does not state the direction of the predicted differences between conditions (e.g. ‘eating chocolate will significantly affect a person’s mood’).
Directional Hypothesis: One tailed. This states the direction of the predicted difference between conditions (e.g. ‘eating chocolate will increase a person’s mood’).
What are the first three steps of conducting research?
- defining an aim
- operationalising variables
- defining a hypothesis
Define the target population
- This describes the group who researchers are studying and want to generalise their results to. For example the target pop might be all females aged 20-30 that shop online.
- Sampling techniques are used to obtain a sample of the target population and are essential to avoid studying entire populations, which would take too long and be too expensive
Describe an important characteristic of a sample
- A sample should be representative of the pop from which it is drawn and should therefore have the same characteristic as the population.
- if the female target population aged 20-30 consists of different social classes and ethnicities, then the sample should reflect this too.
Describe random sampling
- Random sampling is when every member of the target population has the same characteristics of being selected.
- The easiest way to do this is to place all names from the target population in a hat e.g. 100 possible participants from the sixth form that study psychology and Maths.
- We then select our sample, e.g. the first 20 participants’ names that are drawn from the hat.
What are the advantages of random sampling
1) If the target population is large and a large sample is drawn, then it is likely the sample will be representative and therefore results can be generalised from the sample to the target population.
2) There is no researcher bias when selecting the sample, this is because the sample have been chosen by chance without any conscious choice from the researcher. Everyone has an equal chance of being selected.
What are the disadvantages of random sampling
1) It is sometimes difficult to get full details of a target population from which to select a sample. An example might be that it is not possible to get a full list of all of the women aged 20-30 in the UK as some women might not appear on the list due to being in prison, not being registered etc.
2) Not all members of the target population who are selected to take part will be available or willing to take part, making the sample unreliable. Some people might refuse to take part in a study. This could reduce your sample size dramatically too.
Describe systematic sampling
Systematic sampling is a sampling strategy where participants are selected by taking every Nth person from a list. So for example, make a list of the total population of the sixth form that you wish to study, and then select every 6th person on the list. These people become your sample.
What are the advantages and disadvantages of systematic sampling
Advantages:
1) Systematic sampling is far more simple than random sampling as it only requires a list of the target population, and then the researcher decides to select every nth person. Random sampling requires a lot more time and effort (gain the list of the target population, put all of the individual names on bits of paper, and then randomly select a number of people to form the sample)
Disadvantages:
1) The process of selection can interact with a hidden periodic trait within the population. If the sampling technique coincides with the periodicity of the trait, the sampling technique will no longer be reliable
2) Not all members of the target population who are selected to take part will be available or willing to take part, making the sample unrepresentative. Some people might refuse to take part in a study. This could reduce your sample size dramatically too.
Describe stratified sampling
Stratified sampling involves classifying the population into categories and then randomly choosing a sample which consists of participants from each category in the same proportions as they are in the pop
The population are divided into strata in terms of characteristic e.g. age, gender etc. A sample is then selected that reflects these characteristics, e.g. 51% female and 49% male. Data about the sample in the UK can be gained from the Census. Stratified samples can ensure that the sample is representative.
What are the advantages and disadvantages of stratified sampling?
Advantage:
1) The strength of stratified sampling is that all groups within a population are included, therefore the sample should be representative of the population.
Disadvantage:
1) Stratified sampling can be very time consuming as the categories have to be identified and calculated. If you do not have details of all the people in your target population or the relevant strata, you would struggle to conduct a stratified sample.
Describe opportunity sampling
Opportunity sampling involves selecting participants who are readily available and willing to take part.
This is sometimes known as convenience sampling. This involves selecting participants simply because it is convenient to do so. Psychologists might have easy access to a group of people that they know well or have regular contact with. It might therefore be convenient to approach these people to ask them to take part in their research.
What are the advantages and disadvantages of opportunity sampling?
Advantage:
1) This is the easiest and most popular method of ensuring large samples especially when compared to stratified sampling which might be very time consuming and expensive to carry out.
Disadvantage:
1) There is a high chance that the sample will not be representative of the target population. Sometimes people feel obliged to take part in research (especially if someone they know is conducting the research, they might find it hard to say no) even when they do not really want to, this is unethical
Describe volunteer sampling
Volunteer sampling involves people volunteering to participate in a study. The researcher will usually advertise for people to take part in their research. Researchers can advertise by using leaflets, posters, radio or TV broadcasts. These forms of communication means that people take notice of the information and can then decide if they would like to take part in the research and volunteer their time.
What are the advantages and disadvantages of volunteer sampling
Advantage:
1) This method saves the researcher time and effort. The researcher needs to construct some kind of advertisement for the study and then just needs to wait for the participants to come to them to volunteer their time and involvement. This is better than other sampling methods where the researcher needs to ask people to take part and needs their full commitment.
Disadvantage:
1) A certain type of person tends to volunteer (enthusiastic, interested in your topic) and this means that there is a very high chance that the sample obtained will be unrepresentative and will not accurately reflect the target population (volunteer bias).
Describe a pilot study
A pilot study is an initial run-through of the procedures to be used in an investigation; it involves selecting a few people and trying out the study on them. It is possible to save time, and in some cases, money, by identifying any flaws in the procedures designed by the researcher.
What do pilot studies do (research methods)
- A pilot study can help the researcher spot any ambiguities (i.e. unusual things) or confusion in the information given to participants or problems with the task devised.
- Sometimes the task is too hard, and the researcher may get a floor effect, because none of the participants can score at all or can complete the task – all performances are low. The opposite effect is a ceiling effect, when the task is so easy that all achieve virtually full marks or top performances and are “hitting the ceiling”.