what is a control group and what is an experimental group?
control - not exposed to the IV
experimental - exposed to IV
what experimental designs should you use if order effect is a problem? (2)
- counterbalancing or independent groups design
What are descriptive statistics? plus example
used to describe, organise and summarise data. Does not allow us to make conclusions eg. bar graph, averages
What are inferential statistics?
(infer) - allow us to draw a conclusion, connect the sample to the wider population and can decide if its likely that IV affects DV eg. p-value
What is the p-value?
a test that tells us the probability that our results were caused by the dependent variable, not just due to random chance
what is a test of statistical significance?
provide an estimate of how often experimental results might have occurred by chance alone
When is a P-value significant?
p below 0.05 - is statistically significant (results provably due to effect of IV not chance)
p above 0.05 - not statistically significant (results probably due to chance)
eg. 0.16 = 16% chance its random
what must a research hypothesis include?
population, IV, DV, prediction (eg. lower, higher, increased, decreased)
what is an extraneous variable? and what is their problem?
A variable other than the IV that might cause an unwanted change to the DV
- They make it difficult to determine whether any change in the DV was caused solely by the IV and no other factors
what is a cofounding variable? and what is their problem?
an uncontrolled variable that might be confused with the effect of the IV
- cofounding variables actually change the cause and effect relationship between the IV and DV
what is a mean?
measure of central tendency found by adding up all the values and dividing by total number of values
what is a median?
measure of central tendency found by arranging scores from the lowest to the highest and selecting middle score
what is a mode?
measure of central tendency found by selecting most frequently occurring score in a group of scores
what is a generalisation?
a decision or judgement about whether results obtained from a sample are representative of the relevant population
What is random sampling?
ensures that every member of the population of interest has an equal chance of being selected for the sample being used in a study
What is stratified sampling?
ensures the sample contains the same proportions of participants that are found in the population (divides population into strata or sub-groups)
What is convenience sampling?
selection of participants because they are readily available
What is a controlled variable?
when the extraneous variables influence has been removed from an experiment it has been controlled
What is standardisation?
standard procedures for administering a test and interpreting scores are used so there is a consistency
What are participant variables?
individual differences in personal characteristics of research participants that can cofound the results of an experiment e.g. Gender, age
What is the order effect?
where prior knowledge of a task influences a participants performance, which influences results (improved because of practice or impaired because of boredom)
What is counterbalancing?
alters the order that participants experience each condition (helps to reduce order effect)
What is the experimenter effect?
changes in participants behaviour that are caused by the unintentional influence of the experimenter rather than the IV
What are self-fulfilling prophecies?
refers to a prediction that prompts people to act in ways that make the prediction come true (people become what we expect of them)
What is a placebo?
a fake treatment that has no active effect
what is a placebo effect?
changes in behavior caused by the belief that one has been exposed to a treatment that will effect them in some way
What is a double-blind procedure?
neither the experimenter nor the participants know which experimental condition the participants have been allocated to (single blind just participants don’t know)
What is an independent-groups design? (used most frequently) and what is its main goal?
participants randomly allocated to either control or experimental group
- ensures each member of sample has equal chance of being selected to control or experimental group
what is a matched-participants design?
matched participants on variable (sex,age) one put in experimental and one put in control group
What is a repeated-measures design? and why is it used? (3)
the same group of participants makes up the experimental and control groups
- results in minimal differences in personality characteristics
- may result in ‘order effect’
What is convenience sampling? (non-probability sampling)
chooses participants because they are readily available to the researcher (may not rep the population)
what is random allocation?
used to assign participants to experimental or control group where all participants have an equal chance of being allocated to either group
What design should you use to counteract
experimenter effects?
double blind procedure
What design should you use to counteract the placebo effect?
single blind procedure
What design should you use to counteract participant variables?
matched-participants design
What are case studies? (data collection)
an intensive and detailed investigation of a particular event or circumstance and can involve an individual or group of people
what are observational studies? (data collection)
involve collecting data by observing and recording the behaviors as they occur
what are self-reports? (data collection)
involve participants replying to written or oral questions, statements and instructions
what is an experiment? (data collection)
conducted to examine any cause/effect relationship between two variables
What is qualitative data?
describes the changes in the quality of a behaviour; often accounts of personal attitudes or experiences
What is quantitative data?
can be described in quantity or ‘amount’. Usually easy to measure as it is usually expressed as numbers e.g. 160cm tall
What are the 4 sampling techniques?
- random sampling
- stratified sampling
- random stratified sampling
- convenience sampling
What are the 3 types of experimental designs?
- repeated measures
- matched participants
- independent groups
What are the 2 types of procedures?
- double blind
- single blind
What are the four methods of data collection?
- self report
- experiment
- case study
- observational study
what are the 6 participant rights? I Will C - a - D V D
I - informed consent Will - withdrawl rights C - confidentiality a D - deception V - voluntary participation D - debriefing