Experiments Pack Flashcards
What is a laboratory experiment
This is where the IV is manipulated by the researcher and the experiment is carried out in a laboratory or other contrived setting away from the participants environment
What is a field experiment
The IV is manipulated by the researcher but this the experiment is carried out using participants in their normal surroundings
what is a quasi experiment
The IV is naturally occuring e.g weather
what are advantages of lab experiments
easily replicable
reliable
controlled extraneous variables
what are the disadvantages of a lab experiment
lacks ecological validity
higher chance of demand charecteristics
what are the advantages of a field experiment
strong in ecological validity
lesser chance of demand charecteristic
what are the disadvantages of a field experiment
cant control environment
harder to repeat
hard to control extraneous variables
what are the advantages of a quasi experiment
strong ecological validity
what are the disadvantages of a quasi experiment
not easily replicable
cannot control the IV
what is an experimental condition
this experiences the change ir manipulation
what is a control condition
this experiences no change or manipulation
what is an independant variable
This is the variable that is changed during an experiment
what is a dependant variable
This is what you are measuring in an experiment
what is a control variable
this is a variable that is kept the same when you do the experiment
what are the three different types of experimental design
repeated measures design
independant measures design
matched participants design
what is the repeated measures design
This involves using the same people in each condition
what is the independent measures design
This involves using different people in each condition
what is the matched participants design
This involves using different people in each condition but an attempt is made to make the participants as similair as possible on certain key charecterisitics
what are the advantages of repeated measures design
particicpant variables
what are the disadvantages of repeated measures design
demand charecteristocs may be common
order effects
what are the advantages of independent measures design
order effects
what are the disadvantages of independent measures design
participant variables
what are the advantages of matched participants design
less chance of demand charecteristics
no order effects
what are the disadvantages of matched participants design
participant variables
time consuming
high effort
what are extraneous variables
any variable not being investigated that may have an effect on the results of the research.( construct validity )
what are the four extraneous variables
order effects
environmental variables
participant variables
demand charecteristics
what are order effects
when the results are affected by the repitition of a task and not the IV
likely to be a problem for repeated measures design
what are environmental variables
when the results are influenced by the environment they are in and not the IV
most common in a field experiment as the environment cannot be controlled
what are participant variables
when the results are influenced by the individual charecteristics of a participant and not the IV
Most common in individual design as using different participants for each condition
what are demand charecteristics
when the participants do not act naturally as they know the aim of the study
most common in a lab experiment and repeated measures design
what is an alternative hypothesis
this predicts how one variable is likely to affect another variable. an alternative hypothesis always predicts that the IV WILL effect the DV
what is a null hypothesis
predicts that their will be NO EFFECT
What is a two tailed hypothesis
A hypothesis where they make no decision on which way the IV will affect they DV they just say it will effect it
what is a one tailed hypothesis
this predicts he way in which the IV will effect the dv e.g the biv will sinificantly improve this
what is operationalisation
this refers to the process of making variables physically measurable or testable.For example creating a measure for happiness
what is the target population
the group of people the researcher is interested in studying
what is a sample
the actual group of participants used in the research
what are the four different types of sampling
self selecting
opportunity
random
snowball
what is self selecting sampling
This is when people volunteer to take place in a study
what is opportunity sampling
a sample of participants produced by selecting those who are most readily available ata a given time and place
what is random sampling
a technique in which each member of the target population has a equal chance of being selected
what is snowball sampling
when participants are asked to contact their friends and family to also take part in the research. they in turn then ask other people
what are the advantages of self selecting sampling
participants are willing to take part in the research
avoids researcher bias
what are the disadvantages of self selecting sampling
may be demand charecteristics
not as generalisable as only people that want to take part in the study confident/ extroverts
what are the advantages of opportunity sampling
more convenient
easy
quick
what are the disadvantages of opportunity sampling
more ethnocentric as only in one place
not generalsiable
what are the advantages of random sampling
representative of population
no researcher bias
what are the disadvantages of random sampling
participants may not be willing to take part in the study
what are the advantages of snowball sampling
easy to get participants
large sample size
what are the disadvantages of snowball sampling
not generalisable as all friends and family so similar characteristics
what are the 4 ethical considerations
respect
competence
responsibility
integrity
what is qualitative data
data that is NOT represented by numbers
what is quantitative data
data that IS represented by numbers
what are the positives of quantitative data
easily comparable
easily analysed
easy to plot into graphs
what are the negatives of quantitative data
their is no reason for why the data is like that
what are the positives of qualitative data
specific data
explains reasons for results
what are the negatives of qualitative data
hard to compare
hard to plot into graphs
what are the three measures off central tendency
mean
median
mode
how do you calculate the mean
+ up all the numbers
divide by how many different numbers there are
how do you calculate the median
place numbers in order of smallest to largest
the median is the middle value
how do you calculate the mode
it is the most common value in a set of results
whichever value appeared most in the results
what are the advantages of the mean
all data is included no data is missing
what are the disadvantages off the mean
outlier sores can skew the results to not reflect most participants
what are the advantages of the median
not affected by outlier scores
what are the disadvantages of the median
doesn’t take into account all of the data
what are the advantages of the mode
mode can be used for non numerical data
what are the disadvantages of the mode
impossible to calculate if all data is different
what are the three measures of dispersion
range
variance
standard deviation
how do you calculate the range
subtract the smallest value from the largest value
how do you calculate the variance
- for each condition calculate the mean score
- within each condition you then subtract the mean off of each participants score. This gives you the ‘d’ (the difference)
- you then square each d score
- you then add all the d squared scores together
-divide the value ion all added together by n-1 meaning the number of different values subtract one
how do you calculate the standard deviation
square root the variance
what are the advantages of the range
quick
easy to calculate
what are the disadvantages of the range
skewed by outlier scores. for example the anomalous scores are likely to be either the top or bottom value and that hugely affects the range
what are the advantages of the variance
takes into account all of the data
less affected by outlier scores
what are the disadvantages of the variance
only takes into account squared values and therefore not the original units of the data
what are the advantages of the standard deviation
takes into account all of the data
brings values back to normal values
what are the disadvantages of standard deviation
time consuming
difficult to calculate
what is a single blind trial
the patients do not know which study group they are in
however research her do know which groups people are in
what is a double blind trial
where the researchers and the participants don’t know which experimental condition they are in. for example the participants and the researcher wouldn’t know who is taking a placebo
what is researcher bias
when the researchers beliefs or expectations influence the research design or data collection process
what are researcher effects
when a researcher unintentionally or unconsciously influences the outcome of any research they are conducting
what s a raw data table in psychology
data that has been collected by researchers but has not yet been processed or analysed
