Experiments Flashcards
What is an independent variable
The aspect which’s changed in an experiment
What is a dependent variable
What is measured within an experiment
What is a control
Something which is kept the same for all participants
What is an experimental condition
The group who experience the manipulation of the independent variable
What is a control condition
The group who do not experience manipulation of the independent variable
What is a laboratory experiment
One which takes place in a controlled setting
What is a field experiment
One which takes place in a naturalistic setting
What is a quasi experiment
One which has an IV that is not manipulated by the experimenter (race or age)
What are strengths of laboratory experiments
Controlled setting reduces effects of extraneous variables (high construct validity)
Increases internal re,inability as has high level of controls
What are weaknesses of laboratory experiments
Low ecological validity (cannot generalise to real life)
More effort to conduct
People may not act natural (lowers construct validity)
What are strengths of field experiments
High ecological validity as takes place in natural setting
High construct validity (more at ease due to natural environment)
Less effort to conduct People may
What are weaknesses of field experiments
Higher chance of extraneous variables (lowers construct validity)
Participants may have different experiences
What are strengths of quasi experiments
High ecological validity as IV is not manipulated
Helps to study variables that cannot be manipulated
What are weaknesses of quasi experiments
Difficult to conduct
Cannot control some participant variables (lowers construct validity)
What is an extraneous variable
A factor which can influence your dependent variable that are not the IV
They lower construct validity
What are examples of extraneous variables
Situational
Environmental
Participant
Order effects
Demand characteristics
Social desirability bias
What are situational variables
When a feature if the research scenario influenced results
What are environmental variables
When a feature of the research environment influences results (noise or light)
What are participant variables
When the diversity of participants influences results
What are order effects
When participants do better or worse in the second condition due to practice or fatigue
What are demand characteristics
When participants try to work out the sun of the study and as a result, change their behaviour
What is social desirability bias
When participants change their behaviour to look better to others (concealing true behaviour)
What is independent measures
When different people are used in each condition
What are repeated measures
When the same people are used in each condition
What has matched participants design
When similar people are used in each condition of the experiment
What are strengths of repeated measures
Remove effects of any participant variables
Easier to obtain sample as fewer participants needed
What are weaknesses of repeated measures design
Demand characteristics - lowers construct validity
Order effects may influence results unless counterbalanced
What are the strengths of independent measures
Less likely to show demand characteristics as unaware of study’s aim
No order effects as only take part in one condition
What are the weaknesses of independent measures design
Effort to collect more participants
Findings may be influenced by participants variables
What are order effects
When participants do better or worse in the second condition due to practice or fatigue
What are strengths of matched participants
Reduced effects of participant variables
No order effects as different participants for conditions
Lower chance of demand characteristics Social desirability
What are the weaknesses of matched participants
Effort to conduct a protest and match all participants
Cannot control all extraneous variables
What are demand characteristics
When participants try to guess the aim of the study and as a result, change their behaviour to look
What is researcher bias
When the researcher influences the participants behaviour or responses
What is a single blind procedure
Participants are unaware what condition they are in
What is a double blind procedure
Both the participants and researchers are unaware what condition everyone is in
What is an alternative hypothesis
There will be a significant difference in the DV between the IV groups
What is a null hypothesis
There will be no significant difference in the DV between the IV groups. Any difference will be due to chance factors
What is a one tailed hypothesis
The XX group will be significantly better than the XXX group at the DV
Predicts difference and direction
What is a two tailed hypothesis
There will be significant difference in the DV between IV groups
Predicts a significant difference only
What does it mean to operationalise something
Decide how you wish to measure the variables within psychological research
What is self selecting sampling
Participants volunteer to take part in the study
What is opportunity sampling
Participants are obtained at the same time and place of the research
What is snowball sampling
Participants suggest other people to take part in the
What is random sampling
Every member of target population has an equal chance of being selected as a participant
What are strengths of self selecting sampling
Easy to obtain
Already given consent and more likely to continue
No researcher bias
What are the weaknesses of self selecting sampling
Unrepresentative sample
Expensive if there is a money incentive
Could lead to a small sample if lack of volunteers
What are strengths of opportunity sampling
Easy to obtain at time of study
Can obtain target population (depending when and where)
What are weaknesses of opportunity sampling
Unrepresentative sample so low population validity
Researcher bias as they choose who to approach
What are strengths of random sampling
Everyone has an equal chance of being selected
Representative of target population
What are weaknesses of random sampling
Everyone has an equal chance of being selected which can lead to outliers
Sometimes hard to ensure all have an equal chance
Selected people may not being willing to take part
Effort
What are the strengths of snowball sampling
Easy to obtain sample especially if difficult target population
What are the weaknesses of snowball sampling
Not able to generalise sample - family and friends often have similar characteristics
What is primary data
Data obtained by the researchers directly
What is secondary data
Data that is obtained using another source
What is quantitative data
Data represented by numbers such as scores or ratings
What is qualitative data
Data represented by words such as quotes or observations
What are strengths of quantitate data
Easy to compare
No researcher bias
Easy to summarise
Easier to establish reliability of results
What are weaknesses of quantitative data
May not be representative of participants everyday behaviour - low ecological validity
Doesn’t show finer details such as why people behave or feel a certain way
What are strengths of qualitative data
More detail about participant experience
Richer data to improve validity
What are the weaknesses of qualitative data
Harder to compare participants and conditions
Cannot present in a graph
Harder to analyse
Can have researcher bias due to being interpreted multiple ways
What is raw data
The data collected in a study before analysis takes place
What are descriptive statistics
Ways to summarise the findings of a study
What are inferential statistics
Statistical tests to find out the significance of the results
Strengths of the mean
Involves all data which means more representative findings
What are weaknesses of the mean
Includes outliers
Can give decimal figures
What are strengths of the median
Discounts outliers so not skewed
What are weaknesses of the median
Does not include all data collected
May be a decimal figure
What are strengths of the mode
Easy to calculate
A,ways a whole value
Can be done with qualitative data
What are weaknesses of the mode
May be more than one mode
Doesn’t include all data points
What does variance tell you
The spread of each value from the mean
What does standard deviation tell you
The spread of data in relation to the mean
How do you calculate variance
Find differences between scores and mean
Square them
Add them up
Divide by the number of participants minus 1
How to calculate standard deviation
Square root the variance
What are strengths of range
Easy to calculate
Does show the spread between minimum and maximum
What are weaknesses of range
Does not show spread is even
Can be skewed by outliers
Does not include all data
What are strengths of variance
Takes into account all values in data set
Less likely to be affected by outliers Does not
What are weaknesses of variance
More time consuming to calculate
Not in the same units as original measure
What are strengths of standard deviation
Same units as original measure
Easy to calculate if variance is already done
What are weaknesses of standard deviation
Takes into account extreme outliers
