Experimentation Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is validity?

A

Variables are controlled so that any measured effect is likely to be due to the independent variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is reliablity?

A

Consistent values in repeats and independent replicates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is accuracy?

A

Data, or means of data sets, are close to the true value.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is precision?

A

Measured values are close to each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why is a pilot study used?

A

Integral to the development of an investigation, a pilot study is used to help plan procedures, assess validity and check techniques.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What do pilot study allow for?

A

This allows evaluation and modification of experimental design.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What can the use of a pilot study ensure?

A

The use of a pilot study can ensure an appropriate range of values for the independent variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What can a pilot study allow the investigator to establish?

A

It allows the investigator to establish the number of repeat measurements required to give a representative value for each independent datum point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is an independent variable?

A

An independent variable is the variable that is changed in a scientific experiment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a dependent variable?

A

A dependent variable is the variable being measured in a scientific experiment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Are independent and dependent variables continuous or discrete?

A

Independent and dependent variables can be continuous or discrete.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What variable is manipulated by the investigator?

A

Experiments involve the manipulation of the independent variable by the investigator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the experimental treatment group compared to?

A

The experimental treatment group is compared to the control group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a simple experiment?

A

When theres one independent variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Advantage of a simple experiment?

A

The control of laboratory conditions allows simple experiments to be conducted more easily than in a field.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Disadvantage of a simple experiment?

A

Findings found in laboratory conditions may not be applicable to a wider setting.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a multifactorial experiment?

A

When theres more than one independent variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does a multifactorial experiment involve?

A

A multifactorial experiment involves a combination of more than one independent variable or combinations of treatments.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a disadvantage of using groups that already exist?

A

Investigators may use groups that already exist, so theres no truly independent variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are observational studies good and bad at?

A

Observational studies are good at detecting correlation, but since they do not directly test a hypothesis, they are less useful for determining causation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is the independent variable not directly controlled by the investigator in observational studies?

A

In observational studies the independent variable is not directly controlled by the investigator for ethical or logistical reasons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are confounding variables?

A

When other variables besides the independent variable may affect the dependent variable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why must confounding variables be held constant if possible, or at least monitored?

A

Confounding variables must be held constant if possible, or at least monitored so that their effect on the results can be accounted for in the analysis.

24
Q

What is used when confounding variables cannot be controlled?

A

In cases where confounding variables cannot easily be controlled, a randomised block design could be used.

25
Q

What are control results compared to?

A

Control results are used for comparison with the results of treatment groups.

26
Q

What does a negative control provide?

A

The negative control provides results in the absence of a treatment.

27
Q

What is a positive control?

A

A positive control is a treatment that is included to check that the system can detect a positive result when it occurs.

28
Q

When can be placebos be added as a treatment?

A

Placebos can be included as a treatment without the presence of the independent variable being investigated.

29
Q

What is the placebo effect?

A

The Placebo effect is a measureable change in the dependent variable as a result of a patients expectations, rather than changes in the independant variable.

30
Q

What does in vitro refer to?

A

In vitro refers to the technique of performing a given procedure in a controlled environment outside of a living organism.

31
Q

What does in vivo refer to?

A

In vivo refers to experimentation using a whole, living organism

32
Q

What are the advantages of in vitro?

A

Better control of your experiment and any confounding variables.

33
Q

What are the disadvantages of in vitro?

A

not possible for many biological studies.

34
Q

What are the advantages of in vivo?

A

You get a better idea of what is going on inside the cell or organism.

35
Q

What are the disadvantages of in vivo?

A

Living organisms show great variability which cant really be controlled.

36
Q

When is a representative sample of the population selected?

A

Where it is impractical to measure every individual, a representative sample of the population is selected.

37
Q

What determines the appropriate sample size?

A

The extent of natural variation within a population determines the appropriate sample size.

38
Q

What do more variable populations require?

A

More variable populations require a larger sample size.

39
Q

What should a representative sample share?

A

A representative sample should share the same mean and the same degree of variation about the mean as the population as a whole.

40
Q

What is random sampling?

A

In random sampling, members of the population have an equal chance of being selected.

41
Q

What is systematic sampling?

A

In systematic sampling, members of a population are selected at regular intervals.

42
Q

What is stratified sampling?

A

In stratified sampling, the population is divided into categories that are sampled proportionally.

43
Q

What is variation caused by?

A

Variation in experimental results may be due to reliability of measurement methods and/ or inherent variation in the specimens.

44
Q

How can reliability be determined?

A

The reliability of measuring instruments or procedures can be determined by repeated measurements or readings of an individual datum point.

45
Q

What does variation indicate?

A

The variation observed indicates the precision of the measurement instrument or procedure but not necessarily its accuracy.

46
Q

How is natural variation determined?

A

The natural variation in the biological material being used can be determined by measuring a sample of individuals from the population.

47
Q

What gives us an indication of the true value being measured?

A

The mean of these repeated measurements will give an indication of the true value being measured.

48
Q

What is the range of values?

A

The range of values is a measure of the extent of variation in the results.

49
Q

What does it mean if there is a narrow range?

A

If there is a narrow range then the variation is low.

50
Q

How is the reliability of the results determined?

A

Independent data sets should be compared to determine the reliability of the results.

51
Q

What is qualitative data?

A

Qualitative data is subjective and descriptive.

52
Q

What is quantitative data?

A

Quantitative data can be measured objectively, usually with a numerical value.

53
Q

What does ranked data refer to?

A

Ranked data refers to the data transformation in which numerical values are replaced by their rank when the data are sorted from lowest to highest.

54
Q

What is correlation?

A

Correlation is an association and does not imply causation. Causation exists if the changes in the values of the independent variable are known to cause changes to the value of the dependent variable.

55
Q

When does a negative correlation exist?

A

A negative correlation exists when an increase in one variable is accompanied by a decrease in the other variable.

56
Q

What is a positive correlation?

A

A positive correlation exists when an increase in one variable is accompanied by an increase in the other variable.