Unit 3 Key Words

Question 1

Scientific cycle

Answer 1

A guide to carrying out an investigation: observation; hypothesis; experimental design; gathering and recording of data; evaluation of results; conclusion; revise hypothesis.

Question 2

peer reviewed article

Answer 2

specialists with expertise in the relevant field of the study asses the quality of the article

Question 3

The 3 Rs

Answer 3

to ensure animal suffering is kept to a minimum: replacement, reduction, refinement

Question 4

ethics

Answer 4

ideas and beliefs about what type of behaviour is morally right and wrong

Question 5

hypothesis

Answer 5

a prediction of the outcome of the investigation

Question 6

null hypothesis

Answer 6

a statement which proposes that there will be no statistically significant effect as a result of the experiment treatment

Question 7

informed consent

Answer 7

the participant is fully aware of the treatment they will be subjected to and is happy to participate

Question 8

right to withdraw

Answer 8

the participant has the ability to remove themselves from a trial at any time during the study

Question 9

confidentiality

Answer 9

any data collected does not identify the subject and they can remain anonymous, also data is not shared without their consent

Question 10

pilot study

Answer 10

a small scale preliminary study which aims to investigate whether crucial components of a main study will be feasible

Question 11

independent variable

Answer 11

the variable that is changed in a specific experiment

Question 12

dependent variable

Answer 12

the variable that is measured in a scientific experiment

Question 13

confounding variable

Answer 13

variables other than the independent variable and dependent variables that may effect the results of an investigation and therefore need to be considered during the investigation

Question 14

randomised block design

Answer 14

a form of stratified sampling

Question 15

discrete variable

Answer 15

can have a set range of values for example colour, absence/presence

Question 16

continuous variable

Answer 16

can have infinitely many uncountable values, for example length, concentration, wavelength

Question 17

qualitative data

Answer 17

data which is subjective and descriptive

Question 18

quantitative data

Answer 18

data which can be measured objectively, usually with a numerical value

Question 19

ranked data

Answer 19

data transformation in which numerical values are replaced by their rank when data is sorted from highest to lowest

Question 20

simple study design

Answer 20

experimental designed with one independent variable

Question 21

multifactorial study design

Answer 21

experimental designed with more than one independent variable

Question 22

positive correlation

Answer 22

exists when an increase in one variable is accompanied by an increase in another one

Question 23

negative correlation

Answer 23

exists when an increase an increase in one variable is accompanied by a decrease in another one

Question 24

causation

Answer 24

exists if the independent variable is known to change the values of the dependent variable

Question 25

in vitro

Answer 25

preforming in a controlled environment outside of a living organism

Question 26

in vivo

Answer 26

experimentation using a whole living organism

Question 27

mean

Answer 27

the average value of data (total/no. of values)

Question 28

median

Answer 28

the middle value of data

Question 29

mode

Answer 29

the most common value of the data

Question 30

range

Answer 30

a measure of the extent of variation in the results

Question 31

box plot

Answer 31

used to show variation about the mean in one data set or between different data sets. It displays the 5 number summary of a data set : min, max, Q1, Q3, median

Question 32

interquartile range

Answer 32

the difference between Q1 and Q3

Question 33

field study

Answer 33

a study that takes place out of a lab

Question 34

observational study

Answer 34

using groups that already exist so the independent variable isn't directly controlled by the investigator for logical or ethical reasons

Question 35

positive control

Answer 35

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

Question 36

negative control

Answer 36

provides the results in the absence of treatment

Question 37

placebo

Answer 37

a type of negative control which looks exactly like the actual drug

Question 38

placebo effect

Answer 38

a measurable change in the independent variable as a result of a patient's expectations rather than changes in the independent variable, in other words to check if it is phycological

Question 39

double blind study

Answer 39

neither the researcher nor the trial participant will know which group they are until the end of the study

Question 40

sampling

Answer 40

what experiment is conducted on

Question 41

true mean

Answer 41

refers to the population mean

Question 42

representative sample

Answer 42

where it is impractical to measure every individual a representative sample is taken

Question 43

selection bias

Answer 43

selection of a sample in a non-random way so that the sample is not representative of the whole population sampling bias affects validity and reliability

Question 44

random sampling

Answer 44

members of population have a equal chance of being selected. Usually used when population is larger or uniform

Question 45

systematic sampling

Answer 45

members of population are selected at regular intervals e.g. every 3rd person is sampled

Question 46

stratified sampling

Answer 46

population is divided into categories that are then sampled proportionally

Question 47

reliability

Answer 47

constant values are achieved in repeats and independent replicates

Question 48

accuracy

Answer 48

data or means of data sets are close

Question 49

precision

Answer 49

measured values are close together

Question 50

validity

Answer 50

variables controlled so that any measured effect is likely to be due to the independent variable to the true value

Question 51

statistically significant

Answer 51

difference is unlikely to be due to the chance alone

Question 51

standard deviation

Answer 51

a way of telling how much each measurement of a data set differs from the mean of the data set

Question 52

error bar

Answer 52

graphical representations of the variability of data and used on graphs to indicate the error of uncertainty in a reported measure

Question 53

outlier

Answer 53

a data point that is far from other data points

Question 54

anomalous result

Answer 54

a result that doesn't fit in with the pattern of the other results

Question 55

replicate

Answer 55

repeating of measurements of individual data points to indicate how consistent they are

Question 56

independent replicate

Answer 56

a replication of the whole experiment but using freshly prepared materials and on a different day

Question 57

legislation

Answer 57

laws governing various aspects of science. It limits the potential for misuse of studies and data

Question 58

abstract

Answer 58

outlines main findings and aim of project

Question 59

citation/ reference

Answer 59

crediting writers of usedsorces in projects

Question 60

replacement

Answer 60

replacing the animal with an alternative such as tissue cultures or a less sensitive species

Question 61

reduction

Answer 61

using the minimum number of animals in order to obtain robust results

Question 62

refinement

Answer 62

using methods that minimise potential pain suffering or distress on the animals