All Papers: Research Methods Flashcards
What are variables?
In an experiment, there are always two variables:
- The Independent Variable (IV) – which is controlled by the researcher, and defines the groups.
- The Dependant Variable (DV) – which is the result of the study / the thing being measured.
What is meant by operationalising variables?
- stating the variables in a form that can be easily tested.
What is a hypotheses?
- Hypotheses are a prediction of the result of a study.
- Researchers need to create these to direct their research and make it clear what they are trying to show.
What are the two types of hypotheses used in a study?
There are two hypotheses used in a
study:
- Directional / One-tailed (Predicts the direction of the difference)
- Non-Directional / Two-tailed (Predicts that there will be a difference between the conditions, but not which direction it will be in)
What is a null hypotheses?
- No significant difference between
How do you write a correlational hypotheses?
- needs to have an experimental hypothesis (either directional or non-directional) and a null hypothesis written before the study is carried out.
What is meant by experimental design?
- refers to how participants are allocated to the different conditions (or IV groups) in an experiment.
What are the three types of experimental design?
- Independent groups design
- Repeated Measures
- Matched pairs
Explain an Independent groups design.
- Different participants are used in each condition of the
independent variable. - This means that each condition of the experiment includes a different group of participants.
- This should be done by random allocation, which ensures that each participant has an equal chance of being assigned to
Explain a repeated measures design.
- The same participants take part in each condition of
the independent variable.
-This means that each condition of the experiment includes the same group of participants.
Explain a matched pairs design.
- To get the best of both worlds – i.e. no order effects (independent measures design) and no individual differences (repeated measures design)
- This design involves matching participants in each condition as closely as possible (e.g. age, gender, IQ etc.)
- Once a ‘matched pair’ is identified, participants are randomly allocated to either of the conditions.
What is opportunity sampling and its evaluation?
- Opportunity sampling is a sampling technique used to select participants from a target group to take part in a research study. It consists of the researcher selecting anyone who is available and willing to take part in the study.
Strengths:
- This method is easy and inexpensive to carry out unlike random sampling.
Weaknesses:
- The consequent sample may not be representative as it could be subject to bias (e.g. the conveniently located employer may undertake a selection process for job applicants, making it likely that employees possess certain similar characteristics that are unrepresentative of the wider target group).
What is stratified sampling and its evaluation?
- sampler divides or ‘stratifies’ the target group into sections, each showing a key characteristic which should be present in the final sample. Then each of those sections is sampled individually. The sample thus created should contain members from each key characteristic in a proportion representative of the target population.
Strengths:
- It avoids the problem of misrepresentation sometimes caused by purely random sampling.
Weaknesses:
- It takes more time and resources to plan.
- Care must be taken to ensure each key characteristic present in the population is selected across strata, otherwise this will design a biased sample.
What is systematic sampling and its evaluation?
- A systematic method is chosen for selecting from a target group, e.g. every fourth person in a list could be used in the sample. It differs from random sampling in that it does not give an equal chance of selection to each individual in the target group.
Strengths:
- Assuming the list order has been randomised, this method offers an unbiased chance of gaining a representative sample.
Weaknesses:
- If the list has been assembled in any other way, bias may be present. For example if every fourth person in the list was male, you would have only males in your sample.
What is random sampling and it’s evaluation?
- This method gives every member of the target group an equal chance of being selected for the sample (e.g. by assigning a number to each member, and then selecting from the pool at using a random number generator).
Strengths:
- It is widely accepted that since each member has the same probability of being selected, there is a reasonable chance of achieving a representative sample.
Weaknesses:
- Small minority groups within your target group may distort results, even with a random sampling technique.
- It can be impractical (or not possible) to use a. completely random technique, e.g. the target group may be too large to assign numbers to.
What is volunteer sampling and it’s evaluation?
- the sample consists of people who have volunteered to be in the study.
Strengths:
- This often achieves a large sample size through reaching a wide audience, for example with online advertisements.
Weaknesses:
- Those who respond to the call for volunteers may all display similar characteristics (such as being more trusting or cooperative than those who did not apply) thus increasing the chances of yielding an
What are the four types of experiments and their methods?
- Lab: IV and the extraneous variables are controlled- controlled setting.
- Field: the IV is controlled- participants’ real-life environment.
- Natural: the IV naturally occurs
- Quasi: the IV naturally occurs, but it takes place in a lab which is controlled
What is a correlation?
- A test to see whether two variables are related.
Name three types of correlation and their meanings.
- Positive correlation: As one variable increases the other variable increases. e.g. height and shoe size.
Negative correlation: As one variable increases the other variable decreases. e.g. the GCSE grades of students and the amount of time they are absent from school.
- Zero correlation: occurs when a correlational study finds no relationship between variables. e.g. amount of rainfall in Wales and the number of people who have read the Lord of the Rings trilogy.
