VARIABLES
Independent variables
The independent variable is the characteristic of a psychology experiment that is
manipulated or changed by researchers, not by other variables in the experiment.
Example: In an experiment looking at the effects of studying on test scores, studying
would be the independent variable.
Dependent variables
The dependent variable is the variable that is being measured or tested in an
experiment.
Example: In a psychology experiment, researchers are looking at how changes in the
independent variable cause changes in the dependent variable.
Operationalising variables
A variable is an entity, thing or behaviour whose values can change. In all research we
need to give clear definitions of what these variables are and exactly how we are going
to measure them. This is called an operational definition.
Example: One study may operationalise aggression as your score on a self-report
questionnaire whereas another study may operationalise aggression as how many
times you punch the wall.
Extraneous variables
Extraneous variables are all variables, which are not the independent variable, but
could affect the results of the experiment. Control variables will remove extraneous
variables.
Confounding variables
Confounding variables are factors other than the independent variable that may cause
a result.
Example: In your caffeine study it is possible that the students who received caffeine
also had more sleep than the control group.
, HYPOTHESISE
There are two types of hypothesis, directional and non-directional, respectively for
the purpose of statistical testing.
Directional (one-tailed) variables
A directional hypothesis predicts the direction in which change is expected to occur. It
is precise and uses words such as; faster/slower, bigger/smaller, more/less, etc.
Example: Alcohol increases reaction time.
Non-directional (two-tailed) variables
A non-directional hypothesis predicts change and does not specify direction. It is
non-specific and uses words like; effect, change, difference, etc.
Example: Alcohol will affect reaction times.
Null hypothesis: the independent variable will have no effect on the dependent variable.
ETHICS
- Ethics are standards of conduct that distinguish between right and wrong, good
and bad, justices and injustice.
- The primary aim of psychology must be to improve the quality of human life
and to do this it is necessary to carry out research with human participants.
- Research psychologists have a duty to respect the rights and dignity of all
participants. This means they must follow certain moral principles and rules of
conduct, which are designed to protect both participants and the reputation of
psychology. The professional organisation that governs psychology in Britain is
the British Psychological Society (BPS). They have produced a list of ethical
guidelines that all practising psychologists must follow.
- An ethical issue is any situation that repeatedly gives rise to an ethical
dilemma.
, Example: Whether or not to deceive a research participant in a psychological
study in order to gain more worthwhile findings is an ethical issue because it
creates an ethical dilemma to the researcher. (What should they do?)
- One of the main reasons organisations like the BPS have developed ethical
guidelines is that it removes the need for researchers to resolve these
dilemmas on their own.
Ethical guidelines in Psychology:
1. Consent: <16 parents permission
2. Deception: you can lie to the participants in order to avoid demand
characteristics; “screw you” effect or perfect participant.
3. Confidentiality: label participants with a number, initials or pseudonym.
4. Debrief: after research has concluded, explain to the participants what the real
dependent variable was.
5. Withdraw: reassure participants are aware that they can withdraw at any time
and that their data will be deleted.
6. Protection: from both physical and psychological harm.
COST/BENEFIT ANALYSIS (ethical issues conclusions)
Means; costs
- Harm to the participants as a consequence of the research such as distress,
ridicule or loss of self-esteem.
- Must be balanced against the aims.
Ends; benefits
- The value of the research to society must be balanced against the costs to the
participants.
ETHICS; DESIGNING AN EXPERIMENT
Informed consent
Independent variables
The independent variable is the characteristic of a psychology experiment that is
manipulated or changed by researchers, not by other variables in the experiment.
Example: In an experiment looking at the effects of studying on test scores, studying
would be the independent variable.
Dependent variables
The dependent variable is the variable that is being measured or tested in an
experiment.
Example: In a psychology experiment, researchers are looking at how changes in the
independent variable cause changes in the dependent variable.
Operationalising variables
A variable is an entity, thing or behaviour whose values can change. In all research we
need to give clear definitions of what these variables are and exactly how we are going
to measure them. This is called an operational definition.
Example: One study may operationalise aggression as your score on a self-report
questionnaire whereas another study may operationalise aggression as how many
times you punch the wall.
Extraneous variables
Extraneous variables are all variables, which are not the independent variable, but
could affect the results of the experiment. Control variables will remove extraneous
variables.
Confounding variables
Confounding variables are factors other than the independent variable that may cause
a result.
Example: In your caffeine study it is possible that the students who received caffeine
also had more sleep than the control group.
, HYPOTHESISE
There are two types of hypothesis, directional and non-directional, respectively for
the purpose of statistical testing.
Directional (one-tailed) variables
A directional hypothesis predicts the direction in which change is expected to occur. It
is precise and uses words such as; faster/slower, bigger/smaller, more/less, etc.
Example: Alcohol increases reaction time.
Non-directional (two-tailed) variables
A non-directional hypothesis predicts change and does not specify direction. It is
non-specific and uses words like; effect, change, difference, etc.
Example: Alcohol will affect reaction times.
Null hypothesis: the independent variable will have no effect on the dependent variable.
ETHICS
- Ethics are standards of conduct that distinguish between right and wrong, good
and bad, justices and injustice.
- The primary aim of psychology must be to improve the quality of human life
and to do this it is necessary to carry out research with human participants.
- Research psychologists have a duty to respect the rights and dignity of all
participants. This means they must follow certain moral principles and rules of
conduct, which are designed to protect both participants and the reputation of
psychology. The professional organisation that governs psychology in Britain is
the British Psychological Society (BPS). They have produced a list of ethical
guidelines that all practising psychologists must follow.
- An ethical issue is any situation that repeatedly gives rise to an ethical
dilemma.
, Example: Whether or not to deceive a research participant in a psychological
study in order to gain more worthwhile findings is an ethical issue because it
creates an ethical dilemma to the researcher. (What should they do?)
- One of the main reasons organisations like the BPS have developed ethical
guidelines is that it removes the need for researchers to resolve these
dilemmas on their own.
Ethical guidelines in Psychology:
1. Consent: <16 parents permission
2. Deception: you can lie to the participants in order to avoid demand
characteristics; “screw you” effect or perfect participant.
3. Confidentiality: label participants with a number, initials or pseudonym.
4. Debrief: after research has concluded, explain to the participants what the real
dependent variable was.
5. Withdraw: reassure participants are aware that they can withdraw at any time
and that their data will be deleted.
6. Protection: from both physical and psychological harm.
COST/BENEFIT ANALYSIS (ethical issues conclusions)
Means; costs
- Harm to the participants as a consequence of the research such as distress,
ridicule or loss of self-esteem.
- Must be balanced against the aims.
Ends; benefits
- The value of the research to society must be balanced against the costs to the
participants.
ETHICS; DESIGNING AN EXPERIMENT
Informed consent
