Unit 3 Flashcards
Describe the Scientific Cycle
hypothesis
Test the Hypothesis
Collect Data
Analyse data
Accept, Reverse or Reject hypothesis
Analyse, test and revise
When does an experiment produce negative results
hypothesis is wrong
experiment carried out wrong
Why are knowledge of results important
prevents needless duplication of results
Present a more realistic representation
What is a null hypothesis
proposes that there will be no statistically significant effect
\\why is publishing important
others are able to repeat the experiment for validity and reliability
Name types of scientific publication
seminars
conferences
posters
publishing in academic journals
What must be included in a publication
methods
data
analysis
conclusions
What is Peer review
specialists with expertise in the relevant field assess the scientific quality of your report
How can integrity and Honesty be assured in scientific reports
unbiased presentation of results
avoiding plagiarism
reduce opportunity for dishonesty
supply references
what 3 things must you remember with animal studies
replace
reduce
refine
What 3 things must you remember with human studies
informed consent
right to withdraw
confidentiality
What must be carried out before every experiment
risk assessment
What is a hazard
anything that may cause harm
What is a risk
the chance, whether high or low, that somebody COULD be harmed
What is validity
variables are controlled
What is accuracy
data and means close to true value
what is precision
mean values are close to eachother
What is reliability
consistent values in repeats and independant replicates
What is a pilot study
a small preliminary study conducted in order to evaluate the requirements for the experiment
What is an independant variable
the one that changes
What is a dependant variable
the one being measured
What is a confounding variable
other variables besides the independant variable that may affect the dependant variable
Benefits of in vivo studies
provides data for effects
allows study of complex interations
Cons of in vivo
expensive ad time consuming
difficult to interpret results
difficult to prove causation
Benefits of In Vitro
simple and less expensive
easier to control confounding variables
interpretation of results is simpler
Cons of in Vitro
difficult to model complex interactions
Difficult to Extend results to whole organism or different species
When are observational studies used
uses existing groups as its difficult to control independent variables
What are controls used for
comparisson
What is a positive control
system can detect positive result
-effect when there should be an effect
What is a negative control
provides results in the absence of treatment
-no effect when there should be no effect
Types of Sampling
representative - same mean and variation
random - equal chance of selection
systematic - selected at regular intervals
stratisfied - put into categories and sampled proportionately
Difference between a repeat and a replicate
Repeat= repeated using same set in same period
Replicate = repeats whole investigation using new set of equipment
Describe quantitative data
measured objectively (without opinion)
numerical value
take values from a finite set
discrete
Describe Qualitative data
subjective and descriptive
can take any value
continuous
What is ranked data
ordered from smallest to largest
When can a valid conclusion not be made
when the experimental design was flawed
Why should one-off results be treated with caution
not repeated for reliability
not checked experimentally for flaws in experimental design
Why is replication important
limits the potential for misuse of data
What is the purpose of a randomised block design
controlling confounding variables
Discuss the principles and strategies that should be employed in the collection of representative samples.
same mean
same level of variation
random sampling/avoid selection bias
stratified sampling
What happens in a random experimental design
objects or individuals are randomly assigned to an experimental group
why is randomisation the most reliable way of creating similar treatment groups
doesnt involve bias or judgements
What happens inn a randomised block design
subjects divided into similar blocks before randomly assigned to a treatment group
What ca data be described as if it is far from the true value line
unreliable
Why should sample sizes be large
allows results to be tested statistically
What is the use of a pilot study
allows development and improvement of experiment
design is suitable for testing hypothesis
avoid wasting money
avoid flawed techniques
