Chapter 10 Definitions

Question 1

hypothesis

Answer 1

a tentative prediction, usually based on an existing model or theory. Also a tentative explanation of an observation based on an existing model or theory.

Question 2

research question

Answer 2

the specific question that a particular experiment or investigation is attempting to answer

Question 3

logbook

Answer 3

the record of an experiment or investigation kept by the scientist performing the experiments; it is a legal record of the experiments and results

Question 4

reliable

Answer 4

highly likely to be true; a trustworthy source of information or reproducible data

Question 5

reference

Answer 5

the source of a specific piece of information or quotation

Question 6

plagiarism

Answer 6

presenting someone else’s work, including their words and ideas, as your own

Question 7

variables

Answer 7

something that can change or be changed, as distinct from a constant which does not

Question 8

dependent variable

Answer 8

the variable that changes as a result of changes to the independent variable

Question 9

independent variable

Answer 9

a variable upon which another variable depends, something that is changed in an investigation

Question 10

model

Answer 10

a representation of a system or phenomena that explains the system or phenomena. A model may be mathematical equations, a computer simulation, a physical objects, words or other forms

Question 11

theory

Answer 11

a collection of models and concepts that explain specific systems or phenomena. Scientific theories allow predictions to be made and hence are falsifiable

Question 12

falsifiable

Answer 12

able to be disproved

Question 13

primary data

Answer 13

data that you have measured or collected yourself

Question 14

secondary data

Answer 14

data or information that has been collected by someone else

Question 15

line of best fit

Answer 15

the line that most accurately fits the data, usually calculated using linear regression

Question 16

quantitative measurements

Answer 16

a measurement with a numerical value

Question 17

quantitative measurements

Answer 17

a measurement with descriptive or non-numerical results

Question 18

continuous data

Answer 18

able to include any value, sometimes within a fixed range; for example, a rainbow is a continuous spectrum

Question 19

discrete data

Answer 19

able to only include specific values, not continuous; for example, a line spectrum is a discrete spectrum

Question 20

valid

Answer 20

results that are affected only by a single independent variable and hence are reproducible

Question 21

reproducible

Answer 21

giving the same result, within uncertainty, when repeated measurements are made

Question 22

outliers

Answer 22

a data point that does not fit the pattern shown by other measured data points

Question 23

uncertainty

Answer 23

an estimate of the range of values within which the ‘true value’ of a measurement or derived quantity ties

Question 24

analogue

Answer 24

a device or scale that gives a continuous measurement; the scale is continuous and may show any value in a range

Question 25

limit of reading

Answer 25

the minimum uncertainty in a measurement due to the precision with which the scale can be read

Question 26

resolution

Answer 26

the limit of reading or precision of a measuring device

Question 27

precision

Answer 27

the variation in repeated measurements, or the uncertainty of a measuring device

Question 28

measureand

Answer 28

the quantity being measured

Question 29

random errors

Answer 29

a variation that affects a measurement in a random way so that the measurement is as likely to change in any one direction as in another

Question 30

true value

Answer 30

the exact value of a measurand; an idealisation as all measurements have uncertainty and many measurands have values that vary

Question 31

systematic errors

Answer 31

an error that acts to give a consistent offset in data; for example, a zero error

Question 32

scatter graph

Answer 32

a graph or plot showing data points, without a line joining the points, and used to demonstrate or determine a mathematic relationship between variables. The axes are defined by the variables

Question 33

extrapolation

Answer 33

extension beyond the measured range of data to read or construct new data that has not been measured

Question 34

interpolation

Answer 34

to read or construct a new data point that has not been measured but is inside the range of measured data

Question 35

linearise

Answer 35

to make linear; to convert into a form that can be described by a straight line