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Question 1

The central aim of science is to produce knowledge about the world

Answer 1

which involves formulating natural explanations of natural phenomena
- experimentation is one primary strategy used to achieve this aim

Question 2

3 common ingredients in recipes for science and the relationship among them

Answer 2

1) hypotheses ar used to generate expectations
2) expectations are compared with observations
3) that comparison is used to develop, confirm, reject, or refine a hypothesis
* experiments provide a structured way to make observations/collect data

Question 3

Variable

Answer 3

anything that can vary, change or occur in different values
* value of a variable; variable’s state or quantity in some instance

Question 4

in experiments, there are 3 categories of variables:

Answer 4

1) independent variable: a variable that stands alone, whose values vary independently from the values of other variables in an experiment
* when scientists introduce specific changes to a system in an experiment, they do so by changing the value of one or more independent variables (=intervention)

2) dependent variable: a variable whose change depends on another variable
* when scientists change the value of an independent variable, they do so in order to investigate how that change affects one or more dependent variables

3) extraneous variables: other variables besides the independent variable that can influence the value of the dependent variable
* if extraneous variables are not taken into account, they, and not the independent variable, may be responsible for any changes in the dependent variable.
Alternatively, extraneous variables may counteract the influence of the independent variable on the dependent variable.
In these ways, extraneous variables can “confound” the relationship between the independent and dependent variables. If they do so, they are known as Confounding Variables
* Confounding Variables are extraneous variables, which vary in ways that influence the value of the dependent variable in unanticipated ways. Confounding variables can interfere with the accuracy of the conclusions drawn from an experiment

Question 5

Hawthorne Effect (Observer Bias) (Confounding Variable)

Answer 5

experimental participants change their behaviour (unconsciously) in response to being observed

Question 6

Experiments

Answer 6

1) Concrete Physical Aspects
-experiments involve one or more subjects: humans-nonhumans or inanimate objects
- instruments (technical tools or other kinds of apparatus)

2) Technological Aspects
3) Social Aspects

• collecting data involves gathering and often measuring information about the values of variables of interest at particular times, places and contexts

Question 7

Qualitative Data

Answer 7

Information in a non-numerical form

Question 8

Quantitative Data

Answer 8

Information often in a numerical form, that make them easily comparible

Question 9

Crucial Experiment

Answer 9

an experiment that decisively adjudicates between 2 hypotheses, settling which is true

Question 10

The Underdetermination of Hypotheses by Data

Answer 10

the evidence is not sufficient to determine which of multiple hypotheses is true

Question 11

Auxiliary Assumptions

Answer 11

An experiment to test some hypothesis involves a number of Auxiliary Assumptions - assumptions that need to be true in order for the data to have the intended relationship to the hypothesis under investigation

Question 12

3 sources of uncertainty about what an experiment shows

Answer 12

1) extraneous variables
2) unanticipated hypotheses
3) auxiliary assumptions
* one of the primary ways to minimize uncertainty from these sources is Replication

Question 13

Intervention

Answer 13

in a perfectly controlled experiment, experimenters perform an appropriate intervention on an independent variable and then measure the effect of this intervention on the dependent variable.
All extraneous variables are fully controlled, so no confounding variables are possible.

Any change in the behavior of the system thus must be due to the experimenter’s intervention.

This doesn’t eliminate the possibility that some unknown hypothesis also accounts for the data or that some auxiliary assumption was wrong, but it does eliminate the possibility that some confounding variable interfered with the effect

Question 14

To test a hypothesis with an experiment, an important first step is to articulate what the hypothesis would lead you to expect for the outcome of the experiment

Answer 14

Operational Definition is a specification of the conditions when some concept applies, enabling measurement on other kinds of precision.

Cluster indicators Identify several markers of some variable (wealth: yearly income+access to education etc) in order to precisely measure it while not oversimplifying it

Intervention: direct manipulation of the value of a variable (independent variable)

Question 15

Control over variables can be approached in a number of ways:

Answer 15

these can be divided into 2 broad categories: direct and indirect

1) direct variable control: is when all extraneous variables are held at constant values during an intervention
2) indirect variable control: allows extraneous variables to vary in a way that is independent from the intervention. Then, although extraneous variables will vary, they should vary in a way that is the same for the different values of thee independent variable.

• Experimental Group = receives the intervention to the independent variable
• Control Group = experiences the default other value(s) of the independent variable
• 1 approach to indirect variable control is Randomization: the indiscriminate assignment of experimental entities to either the experimental group or the control group
• another condition that must be met for Randomization to be effective is sample size (must be sufficiently large)

An important set of extraneous variables that must be controlled are human expectations

• To control potential Researcher’s Bias: (single) blind experiments (where the researches don’t know)
  Double Blind Experiments (where researchers + subjects don’t know)
  Another way to control for participants’ expectations is deception

Question 16

Elements of the perfectly controlled experiment

Answer 16

1) expectations are clearly articulated: if needed, concepts are defined operationally or using Cluster Indications

2) An intervention is performed on the independent variable

3) all other variables are controlled, either a) directly (by holding all other features constant) or b) indirectly (by comparing an experimental group to a control group, with randomization and a large sample size)

4) the experiment is blind or double-blind, as appropriate, to control for bias

Question 17

Conceptual Vagueness

Answer 17

can make it difficult to rule out the possibility of a false confirmation
* experiments designed to investigate conceptually vague notions are sometimes said to be “ hypothesis operating” rather than “hypothesis testing” since much of the point is to generate new and more refined hypotheses for further investigation

Question 18

A well-designed experiment must anticipate and resolve any issues suggested by these questions

Answer 18

1) can the possibility of a false rejection be ruled out?
2) can the possibility of a false confirmation be ruled out?
3) is the claim at issue conceptually clear?
4) is the difference between predictive success and failure clearly specified?
5) have controls been imposed to eliminate the influence of experimenter or experimental subject expectations?

Question 19

An experiment designed to generate new hypotheses

Answer 19

need not make a specific predition

Question 20

Extraneous Variables (derde variabelen)

Answer 20

elke variabele waarvan betoogd kan worden dat deze mogelijk samenhangt met de uitkomstmaat van je interesse.
Als deze derde variable zowel van invloed is op de onafhankelijke variabele, als op de afhankelijke variabele, dan is deze derde variabele een “confounder” en daarmee een alternatieve verklaring voor het verband tussen de onafhankelijke variabele en de afhankelijke variabele

Question 21

Waarom kun je meer waarde hechten aan onderzoeksresultaten die worden vergeleken met een vooraf opgestelde GEDURFDE voorspelling, dan met een VOORZICHTIGE voorspelling?

Answer 21

bij het uitkomen van een voorzichtige voorspelling zijn er meer alternatieve verklaringen van de resultaten mogelijk dan bij een gedurfde voorspelling. Wel vormt ook het uitkomen van een gedurfde voorspelling nooit definitief bewijs dat de causale hypothese waar is.
* er zullen altijd alternatieve verklaringen mogelijk zijn; dit wordt onderdeterminatie genoemd.

• bij een gedurfde voorspelling wordt een bepaalde grootte van het effect gespecificeerd

Question 22

Interventie/Manipulatie moet valide zijn + Chirurgisch

Answer 22

Fat Handed = weinig precieze manipulatie
* manipulatie moet ook sterk genoeg zijn: dit betekent dat het effect heeft, maar ook voldoende ruimte bieden voor verbetering

Question 23

Is het belangrijker bij Fundamenteel Onderzoek of Toegepast Onderzoek dat interventie chirurgisch moet zijn?

Answer 23

met name voor fundamenteel onderzoek naar de causale relaties tussen variabelen is het een probleem als interventies niet chirurgisch zijn: het wordt dan lastig om causaliteit vast te stellen. Bij toegepast onderzoek is het belangrijker of de interventie werkt.

Question 24

Carey (2011) beschrijft dat een goed opgezet experiment controleert voor variabelen die kunnen leiden tot een onterechte bevestiging of ontkrachting van de causale hypothese die je wilt onderzoeken

Answer 24

1) kijken of het experiment ruimte (nagaan of dit leidt tot uitkomsten die NIET in lijn zijn met verwachtingen) geeft voor “false rejection” (het onterecht verwerpen van de causale hypothese terwijl deze in werkelijkheid waar is).

2) vervolgens moeten we controleren of het experiment ruimte geeft voor “false confirmation” (dus het onterecht bevestigen van de causale hypothese terwijl deze in werkelijkheid niet waar is). Nagaan of het experiment mogelijk leidt tot uitkomsten die in lijn zijn met de voorspellingen, ookal is de hypothese in werkelijkheid niet waar.

Question 25

Elk experiment kan gekarakteriseerd worden op verschillende aspecten (=experimentele opstelling)

Answer 25

1) fysieke aspecten
2) technologische aspecten
3) situationele aspecten
4) temporele aspecten
5) sociale aspecten

Question 26

Ockham’s Razor =

Answer 26

Voorkeur voor Eenvoud