Research Methods Flashcards
What is an operational hypothesis?
it is a research hypothesis that states how the variables being studied will be observed, manipulated, measured and outlines the population from which the sample is selected
What is a population?
Used in psychological research to describe the larger group from which a sample is drawn.
Eg of an operational hypothesis
involving study on depression and exercise
Clinically depressed adult males and females who engage in regular five-day schedule of vigorous walking at 7 kilometers per hour for 30 minutes per day will use fewer negative words when writing a creative story then will clinically depressed people who do not engage in vigorous walking over the 5 days
What is a hypothesis
it is a tentative and testable prediction of the relationship between two or more events or characteristics (an educated guess about what will happen in the research)
What is the independent variable
the variable that is systematically manipulated, changed or varied by the researcher in order to assess it’s effect on the participants response
What is the dependent variable
is the variable that shows any effects of the IV, that is, the change that occurs as a result of the manipulation of the IV
Characteristics of a operational hypothesis
- IV is specified in operationalised terms
- DV is specified in operationalised terms
- the population from which the sample is drawn is stated -it is testable -is an educated guess
- a precisely worded written statement
- expressed clearly
Extraneous variables are
any variables other than the IV that can cause a change in the DV and therefore effects the results of the experiment in an unwanted way
confounding variables are
any variables other than the IV that has had an unwanted effect on the DV, making it impossible to determine which of the variables has produced change in the DV
When does a placebo effect occur
It occurs when there is a change in the responses of participants due to their belief that they are receiving some kind of experimental treatment and they respond in accordance with that belief
Differences between extraneous and confounding variables
extraneous variables are variables that are recognised prior to the experiment that could have an affect on the DV
where as a confounding variable was not accounted for prior to the experiment and actually occurs resulting on confusion as to what caused the change in the DV
Eg of a placebo effect
some people may begin to feel better if they are put on a waiting list for treatment, as compared with how they might feel if they were not on the waiting list
The main 2 types of experimenter effects are…
Experimenter expectancy and self-fulfilling prophecy
an experimenter effect occurs when
there is a change in a participant’s response due to the researcher’s expectations, biasis or actions, rather than to the effect of the IV
Experiment expectancy involves
the cues the researcher gives about the responses participants should give in the experiment
A self-fulfilling prophecy occurs when
the researcher obtains results that they expect to obtain due to cues they provide rather than the IV
Random sampling is
a sampling procedure that ensures every member of the population of research interest has an equal chance of being selected as a participant for a study
commonly used methods of random sampling include
- tossing a coin
- names in a hat
Strengths of random sampling
- it ensures every member of the population of research interest has an equal chance of being selected for the study
- unbiased
- is most likely the sample is representative of the target population
Disadvantages of random sampling
will take a long time if sampling from a large population
What is a biased sample
it is when not everyone in the target population has an equal chance of being selected as a participant
What does stratified sampling involve
it involves dividing the population to be sampled into distinct subgroups (strata) then selecting a separate sample from each stratum in the same proportions as they occur in the target population
What does stratified-random sampling involve
identifying all of the people within each stratum of research interest, then randomly selecting samples of proportionate size from within each stratum
Strength stratified-random sampling
the sample can said to be truly representative and unbiased
limitations of stratified-random sampling
is a very time consuming process and is hard to achieve
What does the experimental group in a study involve
this group is exposed to the experimental condition in which the IV under investigation is present
What does the control group in a study involve
this group is exposed to the control condition in which the IV is absent
what is the reasoning behind using a control group?
it provides a standard which the experimental group can be compared against in order to determine whether or not the IV has caused change in the event being measured (DV)
True or False:
it is not important that the experimental and control groups are as similar as possible in personal characteristics that might cause a change in the DV
False
Random Allocation ensures that
participants selected for the experiment are as likely to be in one group as the other
random allocation can be achieved by
- flipping a coin
- drawing names out of a hat
- a lottery type method
The purpose of random allocation of participants is to
obtain equivalent groups before introducing the IV to the experimental group(s) so that the effects of the IV can be estimated
a single-blind procedure involves
the participants not being aware of the condition of the experiment to which they have been allocated and therefore the experimental treatment
a double blind procedure involves
the participants AND the researcher that is directly involved with the participants being unaware of the conditions that the participants have been allocated to
a double blind procedure is employed to
control possible experimenter effects
a single blind procedure is employed to
control participants’ expectations and other demand characteristics that can influence the results of the study
The 3 types of experimental research designs include
- Matched participants
- independent groups
- repeated measures
repeated measures design involves
each participant being involved in both the experimental and control conditions of an experiment so that the effects of individual participant differences balance out exactly
