My study blog

Subjective testing

Posted by lednum on September 3, 2006

Subjective tests are based on opinions.

This maybe your own opinion, a teacher, a teamte or a coaches opinion

The best form of assessment for subjective data collection is a criteria sheet.

Subjective tests generally assess your performance in a game situation.

 performance analysis

Human memory is limited so that it is almost impossible to remember all the events that take place during an entire competition. Franks and Miller (1986) showed that soccer coaches are less than 45% correct in their post-game assessment of what occurred during 45 minutes of a soccer game. While there is considerable individual variability, this rapid forgetting is not surprising, given the complicated process of committing data to memory and subsequently retrieving it. Events that occur only once in the game are not easily remembered and forgetting is rapid. Furthermore, emotions and personal biases are significant factors affecting memory storage and retrieval.

In most team sports an observer is unable to view, and assimilate, the entire action-taking place on all the playing area. Since the coach can only view parts of game action at any one time (usually the critical areas), most of the peripheral play action is lost. Consequently the coach must then base his post-match feedback on only partial information about a team’s, unit’s or individual’s performance during the game. This feedback is often inadequate, so an opportunity is missed to optimise performances of players and teams.

Problems associated with subjective assessments would seem to present the coach with insurmountable difficulties, particularly if improving the performance of the athlete hinges on the observational abilities of the coach. Despite the importance of observation within the coaching process, very little research has been completed into observational accuracy, the little that has clearly demonstrates that coaches cannot expect to remember even 50% of a performance, in most cases considerably less.

One of the coach’s main tasks is to analyse accurately and assess performance. It would seem then that this couldn’t be carried out subjectively. Any hopes for improvement through feedback would be reduced to chance. How can this be rectified?

Objectivity can be obtained through the use of video, biomechanical systems for fine analyses, or notational analysis. Hand notation systems are in general very accurate but have disadvantages: the more complex ones involve considerable learning time. In addition, the data these systems produce can involve many man-hours to process into output that is meaningful to the coach or athlete: for example it can take as much as 40 hours just to process the data from one squash match.

The introduction of computerised notation systems has enabled these two problems, in particular the data processing, to be tackled positively. Used in real-time analysis or, with video recordings, in post-event analysis, they enable immediate easy data access and the presentation of data in graphical and other pictorial forms more easily understood coaches and athletes. The increasing sophistication, and reducing cost, of video systems has greatly enhanced post-event feedback, from playback with subjective analysis by a coach to detailed objective analysis by means of notation systems (see Brown and Hughes, 1995).

Computers introduce extra problems, of which system-users and programmers must be aware, such as operator errors (e.g. accidentally pressing the wrong key), hardware and software errors. Such undetected perception-errors, where the observer misunderstands an event or incorrectly fixes a position, are particularly problematic in real-time analysis when the data must be entered quickly.

To minimise these problems, careful validation of computerised notation systems must be carried out. Results from the computerised system and a hand system should be compared to assess the accuracy of the former. Reliability tests must also be performed on both hand and computerised systems to estimate the accuracy and consistency of the data.

Four major purposes of notational analysis are:

  1. Analysis of movement
  2. Tactical evaluation
  3. Technical evaluation
  4. Statistical compilation

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