2.2 methods (cognitive) Flashcards
what is a one tailed hypothesis?
a hypothesis that states one condition will be better than the other
what is a two tailed hypothesis?
there will be a difference between conditions
what is a null hypothesis?
there will be no difference between two groups
what is a sample?
a small proportion of participants that you get from the wider population
what is a population?
target group which you want your research to be able to explain their behaviour
what are sampling methods?
ways you can get a sample from your population
e.g : volunteer sampling, opportunity sampling etc.
what is an experiment?
- an investigation where a hypothesis is scientifically tested
- IV is changed and DV is measured
- extraneous variables are controlled
what is a lab experiment?
- experiments that take place in a controlled environment
- there are similar tasks, instructions etc.
- e.g milgram’s, burger, baddeley
what is a field experiment?
experiments that take place in a more everyday surroundings, instead of a lab
- example is sedikikes and jackson
what is a strength of lab experiments?
- easier to replicate as there is a standardised procedure
- allows for precise control of extraneous and independent variables
what is a weakness of lab experiments?
- setting is artificial so it may produce unnatural behaviour that does not reflect real life
- demand characteristics may bias the results and become confounding variables
what are the strengths of field experiments?
- more likely to reflect real life because of its natural setting
- less likelihood of demand characteristics as participants may not know they are being studied
what are the weaknesses of field experiments?
there is less control over extraneous variables which makes it difficult for the study to be replicated exactly the same
what is an independent groups design?
different groups are assigned to different independent variable conditions
what is a repeated measures design?
same group goes through every experimental condition
what is a matched pairs design?
participants who are similar (e.g same gender, race, ability) are put into different groups, they then do different experiment conditions
what are strengths of independent groups design?
- avoids order effects and fatigue effects as each participant is only tested once
- there are less trials for participants meaning they are less likely to guess aim of study
what are the limitations of independent group designs?
- no control for extraneous variables of the participant, such as ability
- needs more participants than repeated measures design, you need more ppl to take part to get the same amount of data
what are order effects?
- participants may get better at a task due to more practice
- better performance in a later condition may have nothing to do with condition itself, but with practice of previous tasks
what are fatigue effects?
- participants may get worse due to being tired
- worse performance in a letter condition may have nothing to do with the condition itself, but the participants are tired or bored
what is a strength of repeated measures design?
if same participants are used, participant variables will be the same for all situations
what are the limitations of repeated measures design?
- order effects
- fatigue effects
how can you limit order/fatigue effects in repeated design?
- counterbalancing
- participants go through conditions in different orders to cancel practice and fatigue effects out
- for example, both groups will drink tea then test then drink coffee then do test but one will drink tea first and vice versa
what are the strengths of a matched pair design?
- participant variables are controlled, making it similar to repeated measures design
- avoids order effects as similar to independent groups design
what are limitations of matched pair design?
- very time consuming to match participant on key variables and lowkey impossible as even twins have differences
- may not be able to control for all participant variables, as there may be some factors that are not accounted for
what is a strength of using a case study to research a method?
- case studies can be used to study rare behaviour
- some types of brain damage are specific to a person and impossible to recreate in lab conditions due to practical limitations
- makes case studies particularly useful for investigating brain damage as it gives a rich and detailed insight into factors that affect human behaviour
what’s a limitation with using case studies as a research method?
- difficult to generalise due to uniqueness of individual
- even when looking at individuals with damage to specific areas of the brain, there may be other damage which is not taken into account
- makes it difficult to assume others with similar brain damage will have similar memory impairments
what are strengths of using standard deviation?
- precise way to measure dispersion of exact values
- easy to calculate if you have a calculator
what are the types of distributions?
- normal distribution
- positively skewed distribution
- negatively skewed distribution
what is a normal distribution?
a probability distribution that is symmetric about the mean (bell curve)
what is a positively skewed distribution?
- mean of the distribution has a positive value and is presented on the right side of the median and mode
- more values are plotted on the left and only a few on the right/tail side
what’s a negatively skewed distribution?
- mean of the distribution is negative or zero and is on the left side of the median and mode
- more values are plotted on the right side of the distribution
what’s a type 1 error?
when the null hypothesis is rejected when it’s true
what’s a type 2 error?
when the null hypothesis is accepted when it’s false
