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.