The Scientific Process: Year 1 Flashcards
What is an aim?
A general statement of what the researcher intends to investigate.
What is a hypothesis?
A statement that can be tested.
What is an alternative hypothesis?
The alternative hypothesis states that there is a relationship between the two variables being studied (one variable has an effect on the other)
The alternative hypothesis predicts that change in the Independent Variable WILL result in SIGNIFICANT changes in the Dependent Variable.
What is a non-directional (two tailed) hypothesis?
Predicts that a change in the IV WILL lead to a SIGNIFICANT change in the DV but does not predict the direction of the change in the DV.
What is a directional (one tailed) hypothesis?
This predicts that a change in the IV WILL lead to a SIGNIFICANT change in the DV in a particularly stated direction.
What is a null hypothesis?
It states that change in the IV WILL NOT result in a SIGNIFICANT change in the DV and that any small changes that do occur will be due to chance factors only.
What does population mean in psychology?
All people or animals who possess a particular characteristic.
What is a target population?
The target population is a group of individuals who meet a particular set of sampling criteria.
E.G = female, 18 years or older, new diagnosis of type II diabetes, not on insulin.
What is a sample?
A group of participants that are selected from a population or a target population.
What is a representative sample?
One which has the same characteristics as the target population AND so can generalise the results to the target population.
What are the different sampling techniques?
1) random sampling
2) stratified sampling
3) systematic sampling
4) volunteer sampling
5) opportunity sampling
What is random sampling?
Selecting the sample in a way that every member of the target population has an equal chance of being selected.
How can random sampling be carried out?
- Give each member of the target population a number)
- Use a random number generator (on a computer) to generate as many numbers/participants as you need.
Give strengths of random sampling?
- Less potential for researcher bias in the selection of participants.
- With a large enough sample there is a good possibility that there will be some participants from all “subsets” of the target population AND SO fairly representative of the target population and so can be generalised back to them.
- Prevents from choosing people who may support their hypothesis
Give weaknesses of random sampling?
- 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.
- Difficult and time consuming to conduct.
- Small minority groups within your target group may distort results, even with a random sampling technique - may still be unrepresentative.
What is stratified sampling?
Most representative sampling method and should be used if the target population contains subsets - a small group in a larger group.
How is stratified sampling carried out?
Here the 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.
Within each subset ensure each member has an equal chance of being selected using random sampling techniques.
What are the strengths of stratified sampling?
- very representative SO can be generalised back to target population
- Free from researcher bias.
- provides a more accurate sampling of population.
What are the weaknesses of stratified sampling?
- 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?
This involves selecting participants at fixed intervals.
How is systematic sampling carried out?
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.
The researcher will decide on an “interval” before selecting the participants so as to gain an appropriate number of participants form the target population.
What are the strengths of systematic sampling?
- It is an unbiased method of sampling as once the researcher has decided on a “system” they cannot then change their minds and not select them as a participant.
Assuming the list order has been randomised, this method offers an unbiased chance of gaining a representative sample.
What are the weaknesses of systematic sampling?
- Less likely to give a representative sample of the target population because not random so we should be cautious about generalising results.
- 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 volunteer sampling?
It is made up of people who offer to take part in a study, often by responding to an advert.
What are the strengths of volunteer sampling?
This often achieves a large sample size through reaching a wide audience, for example with online advertisements.
Relatively simple sampling style as they are giving consent by volunteering and most likely to turn up for the research and do what they are asked to do (practical benefit).
What are the weaknesses of volunteer sampling?
- will give a biased sample as people who respond may not be typical of the target population.
- may be looking for demand characteristics and respond to them (expectancy effect) and in turn help or hinder the experiment.
- Those who respond to the call for volunteers may all display similar characteristics thus increasing the chances of yielding an unrepresentative sample.
What is opportunity sampling?
This involves selecting a sample from people who are willing and able to take part in an experiment when asked to do so.
How is opportunity sampling carried out?
- The researcher approaches who they think would be suitable participants from those available to them.
- those approached then agree or disagree to take part.
What is are the strengths of opportunity sampling?
- quite simple to use and allows the researcher to be more selective in who they approach than simply advertising for volunteers SO the participants should be suitable for the study.
- This method is easy and inexpensive to carry out.
What are the weaknesses of opportunity sampling?
- Biased and unrepresentative SO must be cautious when generalising to the target population.
What are issues that can arise with sampling/what are they often criticised for?
1, being androcentric
2. being ethnocentric
What does androcentrism mean?
It means centred around males WHICH CAN BE AN ISSUE IF the results are also applied to women (beta bias).
What does ethnocentrism mean?
It means centred around one particular culture (most commonly white, western, middle class culture) WHICH CAN BE AN ISSUE IF the results are applied to all cultures (beta bias).
What is a pilot study?
A small-scale trial run of the investigation in which the researcher will keep a record of any problems they encounter and any changes that need to be made.
They will even ask participants at the end whether they understood the instructions clearly or can point to flaw in the design.
What do pilot studies ensure?
That the design and materials researchers have selected are appropriate for their aims and also use it to help eliminate and control for Extraneous Variable’s.
This will increase the chances of conducting reliable and valid research and thus being able to draw strong conclusions from the results.
What is a repeated measures design?
The same participants are used in both conditions.
What are the advantages of the repeated measures design?
- Individual differences are eliminated so this removes subject extraneous variables.
- the most sensitive design as most able to show the effect of IV on the DV as the participants own scores are compared to each other
- it requires less participants than other designs so easier to get the sample.
What are the disadvantages of the repeated measures design?
- order effects (refers to how the positioning of tasks influences the outcome e.g. practice effect or boredom effect on second task) may be experienced
- it may be necessary to use different test materials in each condition (which must be of equal difficulty otherwise introduces a constant error)
- participants are more likely to guess the hypothesis, which may alter their behaviour (help or hinder).
- repeated measures cannot always be used e.g. when the IV is a subject variable.