Research Methods Flashcards
Independent Variable (IV)
- the variable directly manipulated by the researcher in order to examine its effects
- may have 2 or more levels ( ex: different concentrations of IV)
- they are the “conditions being tested in the experiment”
Dependent Variable (DV)
- the variable being measured by the researcher in a study
- is affected by the manipulation of the IV
- outcome of the study
Operationalisation
-making the variables in an investigation detailed and specific
Note:
It is important that both the IV and DV are operationalised so that they are testable and measurable
-We make variables detailed and specific so that another research can know what is measured, changed and how
Extraneous Variables
- factors in an investigation that may interfere with the IV or DV and affect the findings of the study
- situational variables and participant variables
- variable that is not controlled
- need to be controlled to prevent them from affecting the outcome of the study
Confounding Variable
- an extraneous variable that is not controlled and so has an affect on the outcome of the study
- results in the effect of the IV not being truly seen
- it confounds(damages) the results
Situational Variables
-an extraneous variable present in the environment of the study
Ex:
Noise, distractions,light levels and temperature
- How the study was conducted can introduce situational variables
- can influence the study if they vary between conditions
Ex: one group of participants participate in a written task in poor light vs the groups of participants who performs the same task in good lighting
Order effects (under situational variables)
When participants improve or worsen in the second condition because they have practised or become fatigued
If a study requires participants to repeat a test, two possible implications may arise:
Participants have improved
-they became used to the test, repetition( active recall) often results in higher score
Participants have worsened
-they became tired or bored
so they do less well
Demand characteristics (under situational variables)
-when the participants alter their behaviour to meet the perceived aims of the study
Investigator effects
- can also encourage demand characteristics
- when a researcher unintentionally gives clues to the participants about how to behave, altering their behavior
Ex: investigator nodding his head, when the participant does the right thing
Participant Variables
-extraneous variables specific to participants in an investigation, for example, their mood, ability, personality type, upbringing
-participants bring with them various traits and tendencies that could influence the outcomes of the results
esp if a certain type of participant ( ex: a psychotic, aggressive participant )is present in one condition of the
study and not the other
- the researcher only needs to consider what participant variables may influence the results of their study
ex: driving ability is highly unlikely to affect a short-term memory experiment
What to do about Extraneous Variables?
Researchers either eliminate or control them
Eliminating variables= removing the likelihood of them occurring ex: putting a “silence” sign outside ex
Most extraneous variables are difficult to eliminate but they can be controlled
Controlling Situational Variables
Ways to control situational variables
- Standardised Procedure
- To combat the order effect
- counter balancing
- randomisation - To control demand characteristics
- single-blind technique
- double-blind technique
Standardised procedure
-keeping the situation and procedure of a study exactly the same across all conditions of an investigation
example:
if the noise is at a certain level for one condition of the experiment, it should be exactly the same for the other conditions of the study
counterbalancing
a technique used to combat order effects/eliminate the impact of order effects
- “Where half of the participant group experiences condition A then condition B, while the other half experiences condition B then condition A”
- This way the order effects of either improvement or decline in performance are equally distributed in both conditions to cancel each other out
randomisation
-another technique used to combat order effects
- based on the same principle as counterbalancing but this is an investigation
“ where participants are randomly assigned to condition A or B as their first or second test condition”
single-blind technique
- can be used to control demand characteristics
- when the information and aims of the study are withheld from the participants
double-blind technique
- used to control demand characteristics encouraged by investigator effects
- when the information and aims of the study are withheld from both the participants and the researchers
Controlling participant variables
Ways to control participant variables
- Use same participants in both conditions of the study
- so data for each participant compares across all conditions - Use different participants but make sure they are matched on important characteristics
- Random allocation
Random allocation
- can also be used to control participant variables
- “when participants are randomly assigned to one condition of the study or the other” basically random distribution
- not fool proof but its is designed to prevent only a certain type of person being in one condition of the study
Hypothesis
- statement of the predicted outcome
- the way in which a hypothesis is written depends on whether:
1. it is looking for a difference between conditions (as a result of the iv)
2. it is looking for a relationship between variables (in a correlation)/trend
Null hypothesis
-“a prediction that the results will fail to show any difference (or relationship) that is consistent or systematic”
Ex:
for difference between conditions( result of IV)
-There will be no difference in the number of digits recalled whether the participants listened to classical music or jazz; any difference will be due to chance
for relationship between variables (correlation)
-there will be no relationship between the amount of time spent revising and percentage score on the test; any relationship found will be due to chance
Why we add “any difference or relationship will be due to chance”
-because it is highly unlikely that no difference will be found (due to participant variables) , there may be a very small difference (ex: 0.9%) but the difference found will be too small to be due to the manipulation of the IV
Alternative (experimental) hypothesis
- “A prediction of the expected outcome of a study, usually based on a theory”
- can be either a “directional hypothesis” or “non-directional hypothesis”
Directional hypothesis
- “a hypothesis that predicts the direction the results will go in”
- if a theory makes a clear claim, a directional hypothesis can be used ( because the theory already claims what expected direction the results will go in)
ex:
- Adults will recall more digits than children (difference in conditions)
- There will be a negative correlation between self-esteem and depression (relationship/correlation)
Non-directional hypothesis
- “a hypothesis that predicts that a difference /relationship will be found but does not specify what the direction of the difference/relationship will be”
- if a theory does not make a clear claim, or if the evidence is mixed, then we use a non-directional hypothesis
Ex:
- There will be a difference in the number of digits recalled by adults and children (difference in conditions)
- There will be a correlation between self-esteem and depression ( relationship/correlation)
Experimental hypothesis
- the name given to a hypothesis when used in a field or laboratory experiment
Target Population
- the group of people that an investigation is concerned with
- “group of people being investigated in the study”
Sample
a selection of the target population that is directly studied in an investigation
- a sample should represent the nature of the target population
- being representative ensures that the findings of the study can be generalised to the target population
Generalisability
the extent to which the results of the study represent the whole population, not just the sample used
Sampling method
- a technique used to gather a representative group of people as a sample from the target population
Opportunity Sampling Technique
- a technique that recruits participants who happen to be around at the time of the research
This can be done either by”
-asking people to agree to take part
-simply studying people who happen to be there without their agreement ( covert research)
Strengths and Weaknesses of Opportunity Sampling Technique
Strengths
-quickest and simplest sampling technique available to researchers
Weaknesses
Not generalisable
-can lead to a biased sample because not every member of the target population may be around at the time of the study
-only recruits people from a single area whose traits (like personality) may differ from people outside that area
Research design
how participants are allocated to the conditions of the study
Experimental design
the name given to a research design when used in an experiment
Types of research and experimental design
- Independent measures design
- Repeated measures design
- Matched pairs design
Independent measures design
Strengths and Weaknesses and Controlling Problems
“Participants are split into groups with each group tested in only one condition of the study”
Note:
Sometimes this is the only design possible, if age is the IV for example, a participant who is 60 cannot participate in the other condition of the experiment
Strengths
- There are no order effects as participants only take part in one condition of the study.
- less likely to display demand characteristics (less likely to figure out aim of the study)
Weaknesses
- More participants are needed than for a repeated measures design
- There may be individual differences between groups (participant variables)
Controlling Problems
Participants can be randomly allocated to each condition
Repeated measures design
Strengths and Weaknesses and Controlling Problems
The same participants are used in all the conditions of the study
Strengths
- Fewer participants are needed, making it more economical
- There are no individual differences between conditions in the study
Weaknesses
- Demand characteristics are more likely as participants are more able to guess the aim
- Order effects mean that results may reflect practice or fatigue
Controlling Problems
-order effects need to be controlled through counter-balancing or randomisation
Matched pairs design
Strengths and Weaknesses and Controlling Problems
Different participants are used in each condition of the study but are matched for likeness on important characteristics
Strengths
-Fair comparisons can be made between the groups as they are equally matched
Weaknesses
-It is time-consuming to match participants and not all characteristics can be equally matched
Reliability
The consistency of an outcome or result of an investigation (a measure)/ how replicable the study is
-This is important in science because we can trust (rely) on the findings and know that they are not a one-off result
- How we plan and conduct research can affect the reliability of an outcome
- > If a standardised procedure is not used, there can be variability in the procedure , which can result in unreliable findings
-if the results can be replicated
Reliability in Sampling Methods
If a sampling method or technique leads to a biased sample. then the outcome of the research may not be relied upon to occur again, as it could differ if the study was replicated
biased sample
when the sample recruited is made up of a particular type of person which may not reflect the target population
Reliability in experimental designs
In an independent measures design, participants differ between conditions so there is variability between groups because of participant variables. This can lead to unreliable findings.
Validity
refers to the extent to which a study measures what it intends to measure
Internal Validity
“whether the measures used in a test genuinely test what they’re supposed to test”
Ex: if a study is designed to measure aggression in preschool, then it is important that the measures of aggression actually test what they’re supposed test
if you implement a smoking cessation program with a group of individuals, how sure can you be that any improvement seen in the treatment group is due to the treatment that you administered?
Explanation from other sources:
- Internal validity refers to whether the effects observed in a study are due to the manipulation of the independent variable and not some other factor.
- Internal validity is the extent to which a study establishes a trustworthy cause-and-effect relationship between a treatment and an outcome. It also reflects that a given study makes it possible to eliminate alternative explanations for a finding.
External Validity
whether the findings are generalisable to the target population
ex: the sample of preschool children in the investigation must correctly represent the intended target population
Sample error
when a sample differs in qualities from the target population it intends to represent
ex: if different types of people are not proportionately represented in the sample
Validity in sampling methods
if a sample error occurs then the findings of the research are untrue of the target population
Validity in experimental design
The way in which participants are allocated to the conditions of the study ( the experimental design) can affect the validity of the findings
for example
If a repeated measures design is used and order effects are shown, this can mean that the outcome may be a result of practice or fatigue and not the intended variable being investigated
-similarly, demand characteristics are more likely in a repeated measures design, which can also invalidate results
Types of Experiments
- Laboratory Experiment
- Field Experiment
- Natural Experiment
Laboratory Experiment
“An investigation (procedure) staged in an artificial , controlled environment”
Laboratory Experiment
- Researchers stage the conditions of the study and invites participants along
- has an IV and a DV
- aim is to discover cause and effect between these variables by controlling or eliminating extraneous variables
- most useful for studying behavior that might not be affected by the artificial environment of the laboratory (like memory tests) and needs to be tightly controlled
Strengths
- the most scientific of the research methods because of high levels of control
- cause and effect can be established between the IV and DV, which can help with (internal) validity
Weaknesses
- Conducted in an unnatural environment ( thus unnatural behavior may arise)
- Participants are invited to the experiment so they may display demand characteristics
- Considered reductionist because it isolates only the variables under consideration, ignoring other variables that could also be involved
Field Experiment
An experiment (procedure) conducted in a natural environment (“naturalistic environment”)
A Field Experiment….
-still has an IV being manipulated by the researcher and a DV being measured
- level of control of extraneous variables not as high because naturalistic environments are unpredictable
- participants may or may not be aware that they are taking part in a research
- useful when studying behavior that needs to be seen and tested in a natural environment (like conformity and obedience)
Strengths
- conducted in a naturalistic environment so the behavior is natural
- there is a cause and effect between the IV and DV, and some extraneous variables can be controlled
Weaknesses
- Not all extraneous variables can be controlled because it is a real-life environment
- Participants may be unaware that they’re taking part of an experiment so researchers may not have gained information consent
Natural Experiment
“A study that examines a naturally occurring variable in a real life situation”
A natural experiment…
- also occurs in a real-life environment
- has an IV and DV
- but the IV is not manipulated by the researchers as it occurs naturally
Note:
Naturalistic experiments are generally opportunist, which means that they make use of unique and naturally occurring variables that would be otherwise be difficult, or even unethical to set up
Strengths
- The IV is naturally occurring and not manipulated
- The environment in which participants are studied is real and authentic
Weaknesses
- It is not possible to randomly allocate participants to the conditions of the IV, so there may be issues with participant variables that can influence the findings
- extraneous variables are difficult to control
Observations
a research method that involves watching and recording behavior
Types of observation
- Naturalistic observation
- Controlled or structured observation
- Overt observations
- Covert observations
- Participant observations
- Non-participant observations
Naturalistic observation
An observation conducted in an everyday environment where the behavior being studied would normally be seen
- people in a naturalistic observation are expected to behave normally and spontaneously and the researcher will record what they see
- are suitable when studying everyday behavior
Controlled or structured observation
An observation carried out in a laboratory or controlled environment
- a researcher may stage a situation or set up the environment to encourage the behavior they are trying to investigate
- suitable for when it may not be practical for an observer to wait for a behavior to occur naturally
Overt Observation
An observation conducted with the participant’s knowledge that they are being observed as part of an investigation
Note:
- Structured observations tend to be overt because participants are invited to the controlled environment
- Naturalistic observations can be either overt or overt
Covert Observation
An observation conducted without the participant’s knowledge that they are being observed and form part of an investigation
Note:
Naturalistic observations can be either overt or covert
Participant Observation
When an observer is involved in the group that they are observing
Non-participant Observation
the observer watches and records people without being actively involved
