Chapter 4

Question 1

Observation

Answer 1

Registering an empirical phenomenon

Question 2

Manipulation

Answer 2

Changing a variable in a study

Question 3

Intervention

Answer 3

Changing an independent variable

Question 4

Control

Answer 4

Reducing the influence of disturbing factors/variables from influencing the outcome

Question 5

Independent variables

Answer 5

Variables that are hypothesised to affect the dependent variable

Question 6

Dependent variables

Answer 6

The variable that changes depending on the changes to the independent variable

Question 7

Method of difference

Answer 7

By creating two identical groups, and making an intervention on only one of them, the causal effect of that intervention can be studied, since the intervention is the only factor different between the groups

Question 8

Experiment

Answer 8

An observational process characterized by control of the background factors (often through manipulation), intervention on the real target variable through manipulation and observation of the difference caused by this intervention

Question 9

Control group

Answer 9

A contrast class that i not subjected to the intervention, but is similar th-o the treatment group in all other relevant aspects

Question 10

Treatment group

Answer 10

A class that is subjected to the intervention

Question 11

Observational study

Answer 11

An observational process characterized by control of the background factors and observation of an outcome, lacking an intervention

Question 12

Natural experiment

Answer 12

An observational study where circumstances are organized as if there had been manipulation for intervention and control but no manipulation is in fact done

Question 13

Field experiment

Answer 13

An experiment where there is manipulation for intervention, but where several background variables are not controlled, in particular not controlled through manipulation

Question 14

Laboratory experiment

Answer 14

An experiment where there is manipulation for intervention and where all or most relevant variables are controlled

Question 15

Simulation experiment

Answer 15

A model study where the model is created as to mimic an experiment, but where the variable that is intervened on is only represented, rather than actually present

Question 16

Internal validity

Answer 16

An inference in a scientific study (an experiment, an observational study or a model) is internally valid, if the relation between the studied factor and observed effect inferred from the study is indeed true and is not confounded by uncontrolled background factors

Question 17

Confirmation bias/interpretation problem

Answer 17

The observation is registered incorrectly due to psuchological properties of the observer

Question 18

Observer effect/influence problem

Answer 18

The act of observation changes what is observed

Question 19

Placebo effect

Answer 19

The therapeutic effect that an inert substance or treatment, designed to have no therapeutic value, has on a patient

Question 20

Selection bias

Answer 20

A factor influences the selection of the sample, or the division into test and control group, which one did not aim to create

Question 21

Repetition

Answer 21

Performing a study again, exactly following the description of the original study

Question 22

Reproduction

Answer 22

Repeating a study and obtaining the same result as in the original study

Question 23

Replication

Answer 23

Performing a variation of a study with the intention to achieve the same result, where some aspect of the study has been changed to learn how this aspect influenced the result

Question 24

Constancy

Answer 24

Holding background factors constant between test and control group or between trials in a study

Question 25

Elimination

Answer 25

Removing the influence of a background factor

Question 26

Blinding

Answer 26

Eliminating observer effect or the influence problem through limiting information about the study to participants or observers

Question 27

Single blinding/subject blinding

Answer 27

Blinding the participants in a study, for instance about whether they are in the test or control group

Question 28

Experimenter blinding

Answer 28

Blinding the observers in a study, for instance about which subjects are in the test and control group

Question 29

Double blinding

Answer 29

A study is double blind if both subject blinding and experimenter blinding are implemented

Question 30

Separation

Answer 30

Registering the effect of a background variable

Question 31

Randomization

Answer 31

Using a random process to divide into test and control, for instance by flipping a coin

Question 32

Random sampling

Answer 32

Using a random process to collect a sample from the population. Not to be confused with radomization

Question 33

Evidential hierarchies

Answer 33

A ranking of types of evidence based on the processes that produced this evidence

Question 34

Data stratification

Answer 34

Dividing a sample into categories based on specific properties before randomizing ,thus ensuring that these properties are correctly represented in the test and control groups, for instance mirroring their distribution in the population

Question 35

Known factor

Answer 35

A factor which you are aware of constitutes a relevant background factor

Question 36

Unknown factor

Answer 36

A factor which is a relevant background factor, but which you are unaware of

Question 37

External validity

Answer 37

An inference from an experimental system to a different target of interest is externally valid, if the conclusion holds not only for the system but also for the target, for instance an inference from a sample to a population