Unit 3: investigative biology Flashcards
Hypothesis
Predication of a relationship between independent and dependant variables
Null hypothesis
easy to test predications that there is no relationship between the independent and dependant variable
Peer review
appraisal of a piece of work or a scientific report by an independent expert in the relevant field
Plagiarism
copying the work of others without acknowledgement
Reducation
lowering the numbers of an organism used in a study in order to minimise harm to a species
Refinement
the consideration and adoption of methods to minimise harm to a species, including improved animal accommodation and veterinary provision
Replacement
use of alternative to whole organisms in a study to minimise harm to a species
Replication
repeating an experiment either within the study or independently to improve reliability
Review article
expert report that summarises all that is known about an area of interest
Accuracy
The degree of closeness to the true, actual value of measurement
Box plot
Graph showing a data set arranged into numerical order and divided into upper quartile, an interquartile range and a lower quartile
Causation
A link between variables in which one variable is known to be directly affecting the other
Confounding variables
Factors that influence the results of an experiment and cause mistaken associations between the independent and dependent variable to be made
Continuous variable
Variable that can be measured and for which infinite values exist
Correlation
A relationship between two variables that does not imply causation
Dependant variable
Factor that is measured to obtain experimental data
Discrete variable
Variable that must fall into clear-cut categories
Error bar
Line through a data point drawn parallel to an axis showing the variation in the data for that point or the extent of the data for which there is a 95% expectation that the true mean lies along it
In vitro
Experimental produce carried out in laboratory conditions using parts of organisms such as cells or tissues
In vivo
Procedures carried out in laboratory or field conditions using entire, living organisms
Independent data sets
Repeated data sets that are collected in different labs by different workers and at different times but under the same general conditions
Line of best fit
Straight line drawn through a scatter plot that indicates the trend shown by the data
Independent variable
Experimental variable that is purposely altered by the investigator
Mean
Measure of central tendency obtained by summing data and dividing by the number of individual items of data
Mode
Measure of central tendency obtained by indenturing the most common value in a data set
Multi factorial
An experimental situation in which there is more than one dependent variable
Negative control
An experimental aspect in which the independent variable is set at zero, or at no treatment, with the aim of producing a negative result
Observational studies
Work that is usually carried out in the field or in vivo, and usually produces qualitative data
Pilot study
A small-scale study conducted to refine values for independent and controlled variables prior to conducting an experiment
Placebos
Negative controls used in drug and vaccine trials that do not contain the active ingredient being tested
Positive control
An experimental aspect set up to show that system is capable of detecting a positive result should it occur
Precision
The closeness of repeated measurements of a variable
Qualitative data
Data with descriptive values
Quantitative data
Data with numerical values
Random sampling
Sampling in a way to ensure all individuals had an equal chance of being selected in order to obtain a statistically representative sample
Randomised block design
Experimental protocol in which the effects of potentially confounding variables can be reduced
Range
The difference between the two extremes of a set numerical data
Ranked data
Data that has been transformed into arbitrary groups
Reliability
The degree of confidence that an experimental procedure can produce consistent values
Representative sample
A sample that shares the same mean and same degree of variation about the mean as the population as a whole
Standard deviation
Value given for the spread or variation in data
Standard error of the mean
Value for the standard deviations of sample means to the overall mean of a data set
Systematic sampling
Sampling at regular intervals in space or time to take account of a gradient, such as a slop, a tidal cycle or seasonal changes
Stratified sampling
Dividing a population into groups or strata before carrying out the sampling to take account of perceived differences int he individuals, such as size or age
Validity
Refers to the control of variables to produce fair testing
Variable
Factor in an experiment that is changeable or can change
