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Flashcards in How Science Works Deck (19):
1

Accuracy

An accurate measure is one which is close to the true value

2

Anomalous data

Fall outside the normal or expected range
Allows anomalous data to be identified with greater certainty

3

Calibration

Involves fixing known points and constructing a scale between points

4

Causal link

A change in one variable that is caused by a change in another variable

5

Chance

Scientists carry out stats tests to assess the probability that the results of an investigation being due to chance

6

Confounding variable

May affect the outcome of an investigation
Must be kept constant to prevent bias

7

Control group

Treated the same as experimental group to allow comparisons to be made
Ensures data is valid because any differences due to single independent variable

8

Correlation

Relationship between two variables

9

Double-blind trial

Assessing effects of new drug
Neither patients/scientists know which treatment an individual is taking until after trial. Increases validity/avoids bias

10

Errors

Cause readings to be different from true value

11

Fair test

Only iv allowed effect of dv- achieved by keeping all other variables the same

12

Null hypothesis

Stats test requires a clear hypothesis to test

13

Placebo

Given to control group
Ensures validity

14

Protocol

Once an experiment has been done and gives valid and reliable results, can be used by other scientists

15

Random distribution

Arises as a result of chance
Will only be valid if collected at random
Avoids observer bias and allows stats tests to be used

16

Raw data

Processed data- used to calculate percentages and sds

17

True value

This is the accurate value which would be found if the quantity could be measured without errors

18

Zero errors

Caused by instruments with incorrect zero
May occur when zero on colorimeter fails to return to zero

19

Validity

Only if measurements made are effected by the iv only
Not valid if flawed/control variables allowed to change/ observer bias/
Only valid if supported by reliable And valid data to appropriate accuracy