The mood of the participants would be classified as

• the experimenter effect

• the placebo effect

• a non standardised procedure

• an individual participant difference

All participants completing condition 1, condition 2 and then condition 3 would be classified as

• the experimenter effect

• the order effect

• a non standardised procedure

• an individual participant difference

Half of the participants completed the maths test at 9am while the other half completed the maths test at 11pm. The most likely extraneous variable would be

• the experimenter effect

• the order effect

• non standardised procedures

• individual participant differences

All participants are given a new drug designed to improve attention. They show an improvement in focus after taking the drug , this is most likely because of

• the experimenter effect.

• the placebo effect.

• a non standardised procedure.

• an individual participant difference.

Participants are given the same instructions from either a professor, a first year lecturer or a first year university student. The most likely extraneous variable would be classified as

• the experimenter effect.

• the placebo effect.

• a non standardised procedure.

• an individual participant difference.

The varying height and weight of participants would be classified as

• individual participant differences

• the experimenter effect

• non standardised procedure

• the placebo effect

Four different experimenters will be running the experiment at four different locations across Melbourne. The extraneous variables that are most likely to occur are

• individual participant differences

• the experimenter effect

• non standardised instructions and procedures

• the placebo effect

A researcher is investigating the influence of energy drinks on speed. Participants are to complete 6 x 100m sprints over a 30 minute period. The first 3 sprints will be without the energy drink, the last 3 will be 5 minutes after consuming the drink. The most likely extraneous variable is

• the order effect

• the experimenter effect

• non standardised instructions and procedures

• the placebo effect

Participant's prior experience would be classified as

• individual participant differences

• the experimenter effect

• non standardised procedure

• the placebo effect

A researcher is investigating the influence of anti-inflammatory medication on migraine pain. He notices that the group receiving the sugar pill has reported a significant decrease in migraine pain. This is most likely due to

• individual participant differences

• the experimenter effect

• non standardised procedure

• the placebo effect