Reporting And Critical Evaluation Of Biological Research- Reporting And Evaluating Experimental Design

Question 1

What should go in the method section of a project?

Answer 1

A method section of a project should contain sufficent information to allow another investigator to repeat the work. The experimental design should address the intended aim and test the hypothesis. It should allow the treatment effects to be compared to suitable controles

Question 2

What should be taken into consideration when carrying out the method?

Answer 2

-Any confounding variables should be taken into account or standardised across the treatment.
-The validity of an experiment may be compromised when factors other than the independent variable influence the value of the dependent variable. The validity and reliability of the experimental design should be evaluated. An experimental design that does not address the intended aim or test the intended aim or test the hypothesis is invalid

Question 3

What should the method allow?

Answer 3

The treatment to be compared to suitable controles

Question 4

What is a negative control?

Answer 4

set up to find out whether any change occurs in the absent of the active factor- when an effect is not expected

Question 5

What is a positive control?

Answer 5

Set up to find out whether a positive result will occur when it is expected to (i.e. a check of the validity of the experimental procedures)

Question 6

What is selection bias?

Answer 6

The 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 7

How does selection bias affect validity and reliability?

Answer 7

Sometimes selection bias may have prevented a representative sample being selected. Also sample size may not be sufficient to decide without bias whether the change to the independent variable has caused an effect in the dependent variable

Question 8

What is inadequate sample size?

Answer 8

Sample size may not be sufficient to decide without bias whether the change to the independent variable ha dependent an effect in the dependent variable

Question 9

How does inadequate sample size affect validity and reliability?

Answer 9

Inadequate sample size means the sample may not be representative of the whole population