Unit 3 Key Words Flashcards
Scientific cycle
A guide to carrying out an investigation: observation; hypothesis; experimental design; gathering and recording of data; evaluation of results; conclusion; revise hypothesis.
peer reviewed article
specialists with expertise in the relevant field of the study asses the quality of the article
The 3 Rs
to ensure animal suffering is kept to a minimum: replacement, reduction, refinement
ethics
ideas and beliefs about what type of behaviour is morally right and wrong
hypothesis
a prediction of the outcome of the investigation
null hypothesis
a statement which proposes that there will be no statistically significant effect as a result of the experiment treatment
informed consent
the participant is fully aware of the treatment they will be subjected to and is happy to participate
right to withdraw
the participant has the ability to remove themselves from a trial at any time during the study
confidentiality
any data collected does not identify the subject and they can remain anonymous, also data is not shared without their consent
pilot study
a small scale preliminary study which aims to investigate whether crucial components of a main study will be feasible
independent variable
the variable that is changed in a specific experiment
dependent variable
the variable that is measured in a scientific experiment
confounding variable
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
randomised block design
a form of stratified sampling
discrete variable
can have a set range of values for example colour, absence/presence
continuous variable
can have infinitely many uncountable values, for example length, concentration, wavelength
qualitative data
data which is subjective and descriptive
quantitative data
data which can be measured objectively, usually with a numerical value
ranked data
data transformation in which numerical values are replaced by their rank when data is sorted from highest to lowest
simple study design
experimental designed with one independent variable
multifactorial study design
experimental designed with more than one independent variable
positive correlation
exists when an increase in one variable is accompanied by an increase in another one
negative correlation
exists when an increase an increase in one variable is accompanied by a decrease in another one
causation
exists if the independent variable is known to change the values of the dependent variable
in vitro
preforming in a controlled environment outside of a living organism
in vivo
experimentation using a whole living organism
mean
the average value of data (total/no. of values)
median
the middle value of data
mode
the most common value of the data
range
a measure of the extent of variation in the results
box plot
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
interquartile range
the difference between Q1 and Q3
field study
a study that takes place out of a lab
observational study
using groups that already exist so the independent variable isn’t directly controlled by the investigator for logical or ethical reasons
positive control
a treatment that is included to check that the system can detect a positive result when it occurs
negative control
provides the results in the absence of treatment
placebo
a type of negative control which looks exactly like the actual drug
placebo effect
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
double blind study
neither the researcher nor the trial participant will know which group they are until the end of the study
sampling
what experiment is conducted on
true mean
refers to the population mean
representative sample
where it is impractical to measure every individual a representative sample is taken
selection bias
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
random sampling
members of population have a equal chance of being selected. Usually used when population is larger or uniform
systematic sampling
members of population are selected at regular intervals e.g. every 3rd person is sampled
stratified sampling
population is divided into categories that are then sampled proportionally
reliability
constant values are achieved in repeats and independent replicates
accuracy
data or means of data sets are close
precision
measured values are close together
validity
variables controlled so that any measured effect is likely to be due to the independent variable to the true value
statistically significant
difference is unlikely to be due to the chance alone
standard deviation
a way of telling how much each measurement of a data set differs from the mean of the data set
error bar
graphical representations of the variability of data and used on graphs to indicate the error of uncertainty in a reported measure
outlier
a data point that is far from other data points
anomalous result
a result that doesn’t fit in with the pattern of the other results
replicate
repeating of measurements of individual data points to indicate how consistent they are
independent replicate
a replication of the whole experiment but using freshly prepared materials and on a different day
legislation
laws governing various aspects of science. It limits the potential for misuse of studies and data
abstract
outlines main findings and aim of project
citation/ reference
crediting writers of usedsorces in projects
replacement
replacing the animal with an alternative such as tissue cultures or a less sensitive species
reduction
using the minimum number of animals in order to obtain robust results
refinement
using methods that minimise potential pain suffering or distress on the animals
