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”
, Experiments
Review answers
Review questions 1. A general statement about what the researcher
intends to investigate
1. What is an aim? 2. A statement that predicts what is going to happen
2. Define hypothesis 3. Directional, non directional, null hypothesis
3. What are the types of hypothesis? 4. One that predicts the direction of results
4. What is a directional hypothesis? 5. One-tailed
6. One that doesn’t predict the direction of results
5. What is a directional hypothesis known as? 7. Two-tailed
6. What is a non-directional hypothesis? 8. One that says there will be no difference in the
7. What is a non-directional hypothesis known results
as? 9. When there has been previous research that
8. What is a null hypothesis? suggests a particular outcome
10. When there has been no previous research or
9. When should a directional hypothesis be research that doesn’t suggest a particular
used? outcome
10. When should a non-directional hypothesis be 11. Something that can change within an
used? investigation
11. What is a variable? 12. Dependent, independent and control variables
13. Comparison groups
12. What are the types of variables? 14. Clearly defining variables in terms of how they
13. What are experimental conditions? are measured
14. What does operationalisation mean?
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”
, Experiments
Review answers
Review questions 1. A general statement about what the researcher
intends to investigate
1. What is an aim? 2. A statement that predicts what is going to happen
2. Define hypothesis 3. Directional, non directional, null hypothesis
3. What are the types of hypothesis? 4. One that predicts the direction of results
4. What is a directional hypothesis? 5. One-tailed
6. One that doesn’t predict the direction of results
5. What is a directional hypothesis known as? 7. Two-tailed
6. What is a non-directional hypothesis? 8. One that says there will be no difference in the
7. What is a non-directional hypothesis known results
as? 9. When there has been previous research that
8. What is a null hypothesis? suggests a particular outcome
10. When there has been no previous research or
9. When should a directional hypothesis be research that doesn’t suggest a particular
used? outcome
10. When should a non-directional hypothesis be 11. Something that can change within an
used? investigation
11. What is a variable? 12. Dependent, independent and control variables
13. Comparison groups
12. What are the types of variables? 14. Clearly defining variables in terms of how they
13. What are experimental conditions? are measured
14. What does operationalisation mean?
