Science Inquiry

Biology

Hypothesis

A prediction about the relationship between the independent variable and the dependent variable.

*Hypotheses must include the independent and dependent variable.

Variables

Independent:

• The variable that the experimenter deliberately changes to determine how it affects the results (and dependent variable).

Dependent:

• The variable that responds to the changing independent variable.

Controlled:

• Variables that stay constant for the control and experimental groups throughout an experiment so that the changes observed are only due to the independent variable.

Experimental group

The group exposed to the independent variable

Control Groups

The group not exposed to the independent variable; used to provide a comparison with the experimental group.

*Provides comparison data that indicates that it is the independent variable causing the observable changes and not some unidentified variable.

Placebo + Placebo Effect

An inactive drug or procedure applied to the control group.

Placebo effect = A change in participant behaviour due to their expectation of being involved in an experiment.

Single blind

Participants are unaware if they are in the control or experimental group.

Double blind

Both experimenter and participant are unaware of who is in the control and experimental group. Reducing experimenter effect on data collected.

Ethics (Human)

• Informed consent

• Withdrawal rights

• Voluntary participation

• Risk of harm

• Confidentiality

• Anonymity

Informed Consent

All participants should be fully informed about all aspects of the investigation. Then a written, informed permission must be sought from each participant before commencement of the investigation.

Withdrawal Rights

Participants have the right to withdraw from the experiment at any time for any reason.

Voluntary Participation

Participant cannot be coerced, penalised or rewarded around participation in the research.

Risk of Harm

The possibility of harm to the participants should be minimised and the relationship between risk and benefit should be carefully assessed in the context of the investigation.

Confidentiality

Procedures should be adopted so that the identities of the participants is not revealed nor connected to the data collected, except to researchers directly involved in study.

NOTE: Data can be made public but not identity.

Anonymity

The participants in the study remain anonymous even to the researchers. (Participants should not provide identifying information and codes should be used to identify participants).

NOTE: Not always possible depending on investigation.

Animal Ethics

• Replace

• Reduce

• Refine

Replace

If an animal needs to be experimented on then try to use a species of lower sentience. Use insects instead of mammals or use bacteria instead of insects.

Reduce

If you have to use animals in the experiment, then use as few as possible.

Refine

Make sure your experiment puts the animal through the least amount of stress and pain as possible. Try to not have excessive animal deaths.

Validity

DEF: Refers to the extent to which an experiment researches what it says it is investigating. It is a measure of how likely any change in the dependent variable has been caused by manipulating the I.V.

Improving Validity:

• controlling all variable other than the I.V. that will affect the dependent variable.

• Using both experimental and control groups. (e.g. use of placebos and double-blind trials.)

• Increasing randomisation, to reduce sample bias.

Valid experiments = fair tests

Reliability

DEF: refers to the consistency of results achieved. The degree to which an assessment instrument or protocol consistently and repeatedly measures an attribute, achieving similar results for the same population.

Proving Reliability:

• high repeatability

Improving Reliability:

• Using more precise measuring devices

• Increasing the sample size (if practicable considering the context of the investigation)

• Averaging the data results.

Accuracy

The extent to which a measurement result represents the quantity it purports to measure; an accurate measurement result includes an estimate of the true value and an estimate of the uncertainty.

Improved By:

• Correct use of precise measurement tools and procedures.

• Averaging results