Scientific process Flashcards
What is the aim of a study?
A general statement about what the researcher intends to study.
States the purpose of the study.
What is a ‘hypothesis’?
A precise and testable statement that states the relationship between variables.
What are the two types of hypotheses?
Directional
Non-Directional
What is a directional (one tailed) hypothesis?
Predicts the nature of the effect of the independent variable on the dependent variable.”THERE WILL BE NO DIFFERENCE”
What is a non-directional (two tailed) hypothesis?
Predicts that the independent variable will have an effect on the dependent variable, but the direction of the effect is not specified. It just states “THERE WILL BE A DIFFERENCE.”
What is an experimental/ alternate hypothesis?
States that there is a relationship between the two variables being studied (one variable has an effect on the other)
What is a null hypothesis?
Predicts there will not be a difference or effect between two variables.
What is a sample?
Small group of participants the researchers is interested in.
Define the target population.
A specific group of people the researchers is often interested in.
What are two methods to gain a random sample?
Lottery method
Random number generator
What is an opportunity sample?
Recruit those people who are most convenient or most available.
What is a random sample?
A sample of participants produced by using a technique such that every member of the target population being tested has an equal chance of being selected.
What is a volunteer sample?
Also known as a self-selected sample. To recruit participants, advertisements are placed in a newspaper or on a noticeboard.
What is a systematic sample?
A sample obtained by selecting every nth person.
What is a stratified sample?
Subgroups also known as strata within a population are identified. participants are obtained from each of the strata in proportion to their occurrence in the population.
Strengths and weaknesses of opportunity sampling.
+ Quick way and easy of choosing participants
+ Easy to locate a sample.
- It may not provide a representative sample, and could be biased.
- Inevitably biased due to sample being drawn from a small part of the population.
Strengths and weaknesses of random sampling.
+ Least bias method of sampling as all members of the target population have equal chance of being selected.
+ Findings can be applied to the entire population base (generalised).
- May not truly represent the target population.
- It is a complex and time-consuming method of research.
With random sampling, every person or thing must be individually interviewed or reviewed so that the data can be properly collected.
Strengths and weaknesses of Volunteer/self-selected sampling.
+ This method allows the researcher to reach a range of potential ppts as many different people will see the advertisements and be able to respond.
+ Participants will all be happy and willing to participate. (reduces ethical issues)
- It will be biased towards a certain type of person as only people with a personal interest in the research topic will volunteer.
- Results can’t be generalised.
Strengths and weaknesses of stratified sampling.
+ Unbiased.
+ Highly representative of the target population and therefore we can generalise from the results obtained.
- Gathering such a sample would be extremely time consuming and difficult to do.
- Care must be taken to ensure each key characteristic present in the population is selected across strata, otherwise this will design a biased sample.
Strengths and weaknesses of systematic sampling.
+ Should provide a representative sample- unbiased.
+ Gives researchers a degree of control. It can help eliminate cluster selection.
- Very difficult to achieve (i.e. time, effort and money).
- Method isn’t truly random unless you select a random number at random to begin with.
What is sampling bias?
Happens when some members of a sample population are more likely to be selected in a sample than others. Sampling bias limits the generalisability of sample findings because it is a threat to external validity (specifically population validity).
What is generalisation?
Taking something specific and applying it more broadly.
What is a pilot study?
This is a practice run of the proposed research project. Researchers will use a small number of participants and run through the procedure with them. The purpose of this is to identify any problems or areas for improvement in the study design before conducting the research in full. A pilot study may also give an early indication of whether the results will be statistically significant.
For example, if a task is too easy for participants, or it’s too obvious what the real purpose of an experiment is, or questions in a questionnaire are ambiguous, then the results may not be valid. Conducting a pilot study first may save time and money as it enables researchers to identify and address such issues before conducting the full study on thousands of participants.
What is experimental design?
The different ways in which the testing of participants can be organised in relation to the experimental conditions.
What is independent groups design?
Participants are allocated to different groups where each group represents one experimental condition.
What is repeated measures?
All participants take part in all experimental conditions.
What is matched pairs design?
Pairs of participants are first matched on some variable(s) that may affect the DV. Then one member of the pair is assigned to Condition A and the other to Condition B.
What is random allocation?
An attempt to control for participant variables in an independent group design ensures that each participant has the same chance of being in one condition as any other. This is used in IGD.
What is counterbalancing?
A technique used to deal with order effects in a repeated measures design: half the participants experience the conditions in one order, and the other half in the opposite order.
What are order effects?
It’s the order of the conditions having an effect on the participants’ behaviour. Performance in the second condition may be better because the participants know what to do.
What are strengths and weaknesses of independent measures?
- More participants are needed.
- Least effective design for controlling variables.
+ Reduces the chance of demand characteristics.
+ Participants are randomly allocated
What are strengths and weaknesses of repeated measures?
- Increased chance of demand characteristics.
- Same participants are used in both conditions.
+ Fewer participants are needed.
+ Order effects like boredom and fatigue can be controlled through counterbalancing.
What are strengths and weaknesses of matched pairs?
- More participants are needed.
- It is not possible to match all the participant’s characteristics.
+ Identical twins provide researchers with a close match.
+ Good attempt to control participant variables.
Target behaviour is systematically divided up into operationalised specific categories. These are:
Objective
Mutually exclusive
Covers all possible behaviours
What are the 2 sampling procedures?
Time sampling
Event sampling
What is event sampling?
It is where an observer records the number of times a certain behaviour occurs.
What is time sampling?
Time sampling is a method of sampling behaviour in an observation study and is where an observer records behaviour at prescribed intervals. For example, every 10 seconds.
Recording behaviours within a specific time frame.
What are behavioural categories?
An observational study will use behavioural categories to prioritise which behaviours are recorded and ensure the different observers are consistent in what they are looking for.
For example, a study of the effects of age and sex on stranger anxiety in infants might use the following behavioural categories to organise observational data:
What ensures behavioural categories are consistent?
Inter-observer reliability: In order for observations to produce reliable findings, it is important that observers all code behaviour in the same way. For example, researchers would have to make it very clear to the observers what the difference between a ‘3’ on the anxiety scale above would be compared to a ‘7’. This inter-observer reliability avoids subjective interpretations of the different observers skewing the findings.
What is a questionnaire?
A questionnaire is a set of written questions on a topic on which opinions are sought. Questionnaires are frequently used in survey research in which information is gathered regarding people’s attitudes and beliefs.
What are closed questions?
These have specific, limited answers. Often a statement is given to the respondent and they must choose from several fixed responses. The following example is often referred to as a Likert Scale.
What are open questions?
With this type of question, the respondent is given a high level of freedom with their answers. Often the researcher simply asks a question and provides space underneath for the respondent to write their answer. This type of question would collect qualitative data.
What are the strengths and weaknesses of closed questions?
+ It collects quantitative data which means that the researcher can statistically analyse the data, and produce graphs allowing for a thorough numerical analysis to be completed on the data.
+ Easy to replicate the study. This means that since the questions are standardised it is easy to replicate the questionnaire.
- They obtain quantitative data. This is a weakness because the data can be criticised for not accurately representing the complexity of human behaviour.
- Participants may respond in a socially desirable way. This is problematic because it means the findings are not representative of the truth.
What are the strengths and weaknesses of open questions?
+ Collects qualitative data. This is a strength because open questions collect rich qualitative data which helps researchers develop a better, more in-depth knowledge of human behaviour.
+ Easy to replicate the study. This means that since the questions are standardised it is easy to replicate the questionnaire. This is positive because it allows for the questionnaires to be assessed in terms of their reliability.
- Data collected is in qualitative form. This is a weakness because when the researcher comes to analysing the data it is very difficult for them to carry out any statistical tests which means that it can be difficult to draw any firm conclusions on the basis of using inferential statistics.
- Participants may respond in a socially desirable way. This is problematic because it means the findings are not representative of the truth.
What are the ways in designing questionnaires?
Postal questionnaires: This involves sending out questionnaires to people through the post. However, this could cause an unrepresentative sample because only people who have time will respond to the questionnaires, this may exclude people who work, have or have full-time family commitments.
Magazine and newspaper questionnaires: This involves asking the readers to send in the completed questionnaire. However, this could bring about an unrepresentative sample as only readers of that particular magazine will respond to the questionnaire. This will exclude individuals who don’t read this magazine.
How can you design a good questionnaire?
CLARITY: respondent needs to know what is being asked of them.
BIAS: avoid all questions that may lead to ppts answering in a certain way.
ANALYSIS: questions need to be easy to analyse.
PILOT STUDY: carry out a small-scale version in order to make changes.
SAMPLING: use a sample that represents the population.
SEQUENCE: leave more difficult questions to the end.
FILLER QUESTIONS: irrelevant questions should be included to distract ppts, reducing demand characteristics.
What is a variable?
Anything that can vary or change within an investigation
What is the independent variable?
The variable altered/manipulated by the experimenter
What is the dependent variable?
The variable that is measured.
What is meant by operationalising variables?
Explains how a variable is measured or manipulated.
