Psychology A level:
Research methods
, Independent variable = IV
Dependent variable = DV
Control variable = CV
Abbreviations Condition = Cond
Participants = Pps
,Experiments: Aims and hypotheses
What is an aim?
Which hypotheses do I use when?
❏ “A general statement about what the researcher
intends to investigate” ❏ Directional hypothesis should
What is a hypothesis? be used if there has been
❏ “A statement that predicts what is going to happen” previous research which
suggests a particular answer
❏ If there is no previous research
Types of hypotheses:
❏ Directional (one tailed): does predict the direction of or findings from previous
results
❏ “Those who drink energy drinks will be more talkative” research that suggests a
❏ Non directional (two tailed): does not predict the
direction of results
particular answer then non
❏ “There will be an effect on how talkative a person is when directional should be used
they have an energy drink”
❏ Null hypothesis: hypothesis that predicts that there will
be no difference
❏ “There will be no difference in how talkative a person is
when they drink an energy drink”
, Independent Dependent
Experiments: variables variable
Has an effect on
variable
What is a variable?
❏ “Something you can change within an investigation”
Types of variables:
❏ The IV: the variable that the experimenter changes/ manipulates
❏ The DV: the variable that the experimenter is measuring/ observing
❏ The CV: the variables that stay the same
Experimental conditions:
❏ Comparison groups
❏ Cond 1: exposure to 5 hours of sunlight
❏ Cond 2: exposure to no sunlight
, Experiments: variables
Operationalisation of variables:
❏ Researcher must make sure that the IV and DV are clear i.e we need to know
how the variables are being measured
❏ Operationalisation: “ clearly defining variables in term show they can be
measured
Not operationalised: Operationalised:
“People who are exposed to more than 5
“Exposure to more light will have a positive hours of sunlight per day will score more
effect on mood” highly on a happiness questionnaire than
those exposed to less than 5 hours of
sunlight per day”
Research methods
, Independent variable = IV
Dependent variable = DV
Control variable = CV
Abbreviations Condition = Cond
Participants = Pps
,Experiments: Aims and hypotheses
What is an aim?
Which hypotheses do I use when?
❏ “A general statement about what the researcher
intends to investigate” ❏ Directional hypothesis should
What is a hypothesis? be used if there has been
❏ “A statement that predicts what is going to happen” previous research which
suggests a particular answer
❏ If there is no previous research
Types of hypotheses:
❏ Directional (one tailed): does predict the direction of or findings from previous
results
❏ “Those who drink energy drinks will be more talkative” research that suggests a
❏ Non directional (two tailed): does not predict the
direction of results
particular answer then non
❏ “There will be an effect on how talkative a person is when directional should be used
they have an energy drink”
❏ Null hypothesis: hypothesis that predicts that there will
be no difference
❏ “There will be no difference in how talkative a person is
when they drink an energy drink”
, Independent Dependent
Experiments: variables variable
Has an effect on
variable
What is a variable?
❏ “Something you can change within an investigation”
Types of variables:
❏ The IV: the variable that the experimenter changes/ manipulates
❏ The DV: the variable that the experimenter is measuring/ observing
❏ The CV: the variables that stay the same
Experimental conditions:
❏ Comparison groups
❏ Cond 1: exposure to 5 hours of sunlight
❏ Cond 2: exposure to no sunlight
, Experiments: variables
Operationalisation of variables:
❏ Researcher must make sure that the IV and DV are clear i.e we need to know
how the variables are being measured
❏ Operationalisation: “ clearly defining variables in term show they can be
measured
Not operationalised: Operationalised:
“People who are exposed to more than 5
“Exposure to more light will have a positive hours of sunlight per day will score more
effect on mood” highly on a happiness questionnaire than
those exposed to less than 5 hours of
sunlight per day”
