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