7.1: Types of experiment Flashcards
Laboratory experiments
Laboratory experiments are experiments conducted in a controlled environment, using standardised procedure, with participants randomly allocated to experimental groups, allowing the establishment of causality
An example of a laboratory experiment
An example of a laboratory experiment is Baddeley’s (1966) study of encoding in memory
Advantages of laboratory experiments:
1. There is a high degree of what?
An advantage of a laboratory experiment is that there is a high degree of control
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control what?
Experimenters control all variables
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are what?
Experimenters control all variables and the IV and DV are:
- Precisely operationalised (defined)
- Measured
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to what?
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater:
- Accuracy
- Objectivity
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater accuracy and objectivity.
2. R?
An advantage of a laboratory experiment is replication
Advantages of laboratory experiments: 1. There is a high degree of control. Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater accuracy and objectivity. 2. Replication. Other researchers can do what?
Other researchers can repeat the experiment to check results
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater accuracy and objectivity.
2. Replication.
Other researchers can repeat the experiment to check results.
3. C and what?
An advantage of a laboratory experiment is:
- Cause
- Effect
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater accuracy and objectivity.
2. Replication.
Other researchers can repeat the experiment to check results.
3. Cause and effect.
As all other variables are controlled, the effect (change in the value of the DV) must be what?
As all other variables are controlled, the effect (change in the value of the DV) must be caused solely by the manipulation of the IV
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater accuracy and objectivity.
2. Replication.
Other researchers can repeat the experiment to check results.
3. Cause and effect.
As all other variables are controlled, the effect (change in the value of the DV) must be caused solely by the manipulation of the IV.
4. I of what?
An advantage of a laboratory experiment is isolation of variables
Advantages of laboratory experiments:
1. There is a high degree of control.
Experimenters control all variables and the IV and DV are precisely operationalised (defined) and measured, leading to greater accuracy and objectivity.
2. Replication.
Other researchers can repeat the experiment to check results.
3. Cause and effect.
As all other variables are controlled, the effect (change in the value of the DV) must be caused solely by the manipulation of the IV.
4. Isolation of variables.
In the laboratory, what can happen?
In the laboratory, individual pieces of behaviour can be:
- Isolated
- Rigorously tested
Weaknesses of laboratory experiments:
1. Experimenter what?
A weakness of laboratory experiments is experimenter bias
Weaknesses of laboratory experiments:
1. Experimenter bias.
What can affect results?
Experimenters’ expectations can affect results
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be what?
- Experimenters’ expectations can affect results
2. Participants may be influenced by these expectations
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems doing what?
A weakness of laboratory experiments is problems operationalising the:
- IV
- DV
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become what and do what?
To gain precise measurements can:
- Become too specific
- Not relate to wider behaviour
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
Example
For example, defining ‘getting fatter’ as putting on 2 pounds per week
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low what?
A weakness of laboratory experiments is low external (ecological) validity
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations what?
High degrees of control make experimental situations:
- Artificial
- Unlike real life
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations artificial and unlike real life.
Therefore, it can be difficult to do what?
Therefore, it can be difficult to generalise results to other settings
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations artificial and unlike real life.
Therefore, it can be difficult to generalise results to other settings.
Laboratory settings can be what?
Laboratory settings can be intimidating places
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations artificial and unlike real life.
Therefore, it can be difficult to generalise results to other settings.
Laboratory settings can be intimidating places, so people may not do what?
Laboratory settings can be intimidating places, so people may not act normally
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations artificial and unlike real life.
Therefore, it can be difficult to generalise results to other settings.
Laboratory settings can be intimidating places, so people may not act normally.
4. What characteristics?
A weakness of laboratory experiments is demand characteristics
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations artificial and unlike real life.
Therefore, it can be difficult to generalise results to other settings.
Laboratory settings can be intimidating places, so people may not act normally.
4. Demand characteristics.
Participants are aware they’re being what?
Participants are aware they’re being tested
Weaknesses of laboratory experiments:
1. Experimenter bias.
Experimenters’ expectations can affect results and participants may be influenced by these expectations.
2. Problems operationalising the IV and the DV.
To gain precise measurements can become too specific and not relate to wider behaviour.
3. Low external (ecological) validity.
High degrees of control make experimental situations artificial and unlike real life.
Therefore, it can be difficult to generalise results to other settings.
Laboratory settings can be intimidating places, so people may not act normally.
4. Demand characteristics.
Participants are aware they’re being tested and so may do what?
Participants:
- Are aware they’re being tested
- So may unconsciously alter their behaviour
Field experiments
Field experiments are experiments conducted in a naturalistic environment, in ‘real world’ settings rather than the laboratory, where:
- The researchers manipulate the IV
- As many other variables as possible are controlled
An example of a field experiment
An example of a field experiment is Bickman’s (1974) study of obedience
Natural experiments
Natural experiments are experiments where the IV varies naturally
Natural experiments are experiments where the IV varies naturally.
The experimenter does not manipulate it, but records what?
The experimenter does not manipulate it, but records the effect on the DV
Natural experiments are experiments where the IV varies naturally.
The experimenter does not manipulate it, but records the effect on the DV.
Example
For example, Costello et al. (2003) were studying the mental health of Native Americans on a reservation
Natural experiments are experiments where the IV varies naturally.
The experimenter does not manipulate it, but records the effect on the DV.
For example, Costello et al. (2003) were studying the mental health of Native Americans on a reservation.
What happened during the study?
During the study, a casino opened
Natural experiments are experiments where the IV varies naturally.
The experimenter does not manipulate it, but records the effect on the DV.
For example, Costello et al. (2003) were studying the mental health of Native Americans on a reservation.
During the study, a casino opened, giving an opportunity to study what?
During the study, a casino opened, giving an opportunity to study the effect of decreasing poverty on mental health
Quasi experiments
Quasi experiments are where the researcher is unable to:
1. Freely manipulate the IV, because it occurs naturally
Or,
2. Randomly allocate the participants to the different conditions
In quasi experiments, the IV occurs naturally.
Example
For example, in a study of gender, where:
1. Males
2. Females
are compared
When are natural and quasi experiments often used?
- Natural
- Quasi
experiments are often used when it is unethical to manipulate an IV
Natural and quasi experiments are often used when it is unethical to manipulate an IV.
In such studies, what is not possible?
In such studies, random allocation of participants is not possible
Advantages of field and natural experiments:
1. High what?
An advantage of:
1. Field
2. Natural
experiments is high ecological validity
Advantages of field and natural experiments:
1. High ecological validity.
Due to the ‘real world’ environment, results what?
Due to the ‘real world’ environment, results:
- Relate to everyday behaviour
- Can be generalised to other settings
Advantages of field and natural experiments:
1. High ecological validity.
Due to the ‘real world’ environment, results relate to everyday behaviour and can be generalised to other settings.
2. No what?
An advantage of:
1. Field
2. Natural
experiments is no demand characteristics
Advantages of field and natural experiments:
1. High ecological validity.
Due to the ‘real world’ environment, results relate to everyday behaviour and can be generalised to other settings.
2. No demand characteristics.
Often participants are what?
Often participants are unaware of the experiment
Advantages of field and natural experiments:
1. High ecological validity.
Due to the ‘real world’ environment, results relate to everyday behaviour and can be generalised to other settings.
2. No demand characteristics.
Often participants are unaware of the experiment and so there are no what?
Often participants are unaware of the experiment and so there are no demand characteristics
Weaknesses of field and natural experiments:
1. Less what?
A weakness of:
1. Field
2. Natural
experiments is less control
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control what?
It is more difficult to control extraneous variables
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so what?
It is more difficult to control extraneous variables, so causality is harder to establish
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. R what?
A weakness of:
1. Field
2. Natural
experiments is replication
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to do what, since the conditions are what?
It is difficult to exactly repeat:
1. Field
2. Natural
experiments to check the results, since the conditions are never exactly the same again
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has controlled or not controlled.
3. E what?
A weakness of:
1. Field
2. Natural
experiments is ethics
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has controlled or not controlled.
3. Ethics.
When participants are not aware that they are in an experiment, it incurs what?
When participants are not aware that they are in an experiment, it incurs a lack of informed consent
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has controlled or not controlled.
3. Ethics.
When participants are not aware that they are in an experiment, it incurs a lack of informed consent.
This applies more to what?
This applies more to field experiments
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has controlled or not controlled.
3. Ethics.
When participants are not aware that they are in an experiment, it incurs a lack of informed consent.
This applies more to field experiments, since what?
This applies more to field experiments, since in natural/quasi experiments the IV:
- Occurs naturally
- Is not manipulated by the experimenter
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has controlled or not controlled.
3. Ethics.
When participants are not aware that they are in an experiment, it incurs a lack of informed consent.
This applies more to field experiments, since in natural/quasi experiments the IV occurs naturally and is not manipulated by the experimenter.
4. S what?
A weakness of:
1. Field
2. Natural
experiments is sample bias
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has controlled or not controlled.
3. Ethics.
When participants are not aware that they are in an experiment, it incurs a lack of informed consent.
This applies more to field experiments, since in natural/quasi experiments the IV occurs naturally and is not manipulated by the experimenter.
4. Sample bias.
Samples may not be what, since what?
Samples may not be comparable to each other, since participants are not randomly allocated to groups
If an experiment is high in replication, it is high in what?
If an experiment is high in replication, it is high in reliability
Mundane realism
Mundane realism is:
- The extent to which an experiment reflects the real world
- How ‘real to life’ it is
Weaknesses of field and natural experiments:
1. Less control.
It is more difficult to control extraneous variables, so causality is harder to establish.
2. Replication.
It is difficult to exactly repeat field and natural experiments to check the results, since the conditions are never exactly the same again.
They are low in reliability, as you can’t repeat the experiment, because you don’t know what?
Field and natural experiments are low in reliability, as you can’t repeat the experiment, because you don’t know what the experimenter has:
1. Controlled
Or,
2. Not controlled
Advantages of quasi experiments:
1. Reactions of test subjects are more likely to be what?
An advantage of quasi experiments is that reactions of test subjects are more likely to be genuine
Advantages of quasi experiments:
1. Reactions of test subjects are more likely to be genuine, because it is what?
Reactions of test subjects are more likely to be genuine, because it is not an artificial research environment
Advantages of quasi experiments:
- Reactions of test subjects are more likely to be genuine, because it is not an artificial research environment.
- Quasi experiments can be very useful in identifying what?
An advantage of quasi experiments is that quasi experiments can be very useful in identifying general trends from the results
Advantages of quasi experiments:
- Reactions of test subjects are more likely to be genuine, because it is not an artificial research environment.
- Quasi experiments can be very useful in identifying general trends from the results.
- Quasi experiments reduce the what that may surround the pre-selection and random assignment of test subjects?
An advantage of quasi experiments is that quasi experiments reduce the:
1. Difficulty
2. Ethical concerns
that may surround the pre-selection and random assignment of test subjects
Advantages of quasi experiments:
1. Reactions of test subjects are more likely to be genuine, because it is not an artificial research environment.
2. Quasi experiments can be very useful in identifying general trends from the results.
3. Quasi experiments reduce the difficulty and ethical concerns that may surround the pre-selection and random assignment of test subjects.
Example
For example, if examining the effects of cigarette smoking by pregnant women on the fetus, it would be unethical to randomly assign pregnant women to groups
Weaknesses of quasi experiments:
1. Statistical analyses may not be what?
A weakness of quasi experiments is that statistical analyses may not be useful
Weaknesses of quasi experiments:
1. Statistical analyses may not be useful, due to what?
A weakness of quasi experiments is that statistical analyses may not be useful, due to the:
- Lack of randomisation
- Threats to internal validity
Weaknesses of quasi experiments:
- Statistical analyses may not be useful, due to the lack of randomisation and the threats to internal validity.
- The lack of random assignment into test groups leads to what?
A weakness of quasi experiments is that the lack of random assignment into test groups leads to non-equivalent test groups
Weaknesses of quasi experiments:
- Statistical analyses may not be useful, due to the lack of randomisation and the threats to internal validity.
- The lack of random assignment into test groups leads to non-equivalent test groups that can do what?
A weakness of quasi experiments is that the lack of random assignment into test groups leads to non-equivalent test groups that can limit the generalisability of the results to a larger population
Advantages of laboratory experiments - Ethical considerations:
It is easy to do what?
An advantage of laboratory experiments is that it is easy to:
- Gain informed consent
- Give participants the right to withdraw
Advantages of field experiments - Ethical considerations:
It is easy to do what?
An advantage of field experiments is that it is easy to:
- Gain informed consent
- Give participants the right to withdraw
Disadvantages of natural experiments - Ethical considerations:
Participants probably do not know what?
A disadvantage of natural experiments is that participants probably do not know that they’re taking part in an experiment
Disadvantages of natural experiments - Ethical considerations:
Participants probably do not know that they’re taking part in an experiment and so what become serious concerns?
A disadvantage of natural experiments is that participants probably do not know that they’re taking part in an experiment and so:
1. Informed consent
2. The right to withdraw
become serious concerns
External (ecological) validity
External (ecological) validity is the extent to which the findings of a research study are able to be generalised to real life settings
