The Effects of leading questions on Eyewitness Testimony

Method

Design

A laboratory experiment was used for this piece of research. This was chosen as in these settings there is a high degree of control for the researcher who is more able to control variables for a more effective and reliable piece of research. Also these types of experiments are usually easier to replicate if results need to be checked or reaffirmed. It is also easier to avoid extraneous or confounding variables, which could affect results. Examples of extraneous variables that could arise in this experiment could be distractions in the room where the experiment may take place, individual differences e.g. the moods of the participants may vary etc. To avoid this, the two conditions were set in the same room at the same time of day. This room was as devoid of colour and distraction as was possible in attempts to keep the participants on focussing on the task at hand. Other factors that could have affected the status/mood of the participant could have been weather or temperature. This was also avoided by keeping participants indoors in a classroom. This classroom had air conditioning facilities, these ensured that the room was kept at a comfortable temperature to avoid distraction.

However there are some factors that need to be considered when conducting laboratory experiments for instance participants may change their behaviour if they are trying to guess or conform to experimenter’s expectations. An example of this could be that participants may give answers that they know to be incorrect during this experiment, which would affect the validity of the results. This is called demand characteristics and can be to the experimenter’s detriment. To avoid this, the true purpose of the experiment was not revealed until the debriefing at the end of the experiment. This reduced the likelihood of participants giving answers that they believed to be incorrect or misleading to affect the results of the experiment. Also, these types of experiments tend to have low ecological validity, as high levels of control can lead to artificial situations, which make the results less applicable to every-day life. This directly affects my experiment, as it is an attempt to discover how valid eyewitness Testimony is in everyday life. In attempts to make the results of the study applicable to everyday life, a video clip was used, as television and films are often watched and enjoyed throughout the population that was targeted through the study.

The Independent Variable that was manipulated was the different questions used during the course of the experiment (leading/non-leading questions). The Dependant Variable the accuracy of eyewitness testimony, which was measured by the levels of incorrect answers given.

An Independent groups design was used for this experiment. This means that different participants were used in both conditions. This method was chosen to avoid order effects, which could be a result of using the same participants twice, this could have affected the result data collected. This also reduces the chances of demand characteristics arising, as participants will be less likely to guess the purpose of this experiment having completed only two different questionnaires. Also as both conditions could be tested at the same time this method would be more time efficient than others (e.g. repeated measures designs where ...