What measuring instruments do computer engineers use

General information on measuring instruments

Before starting any study, the most suitable measuring instruments for answering the research question formulated must be selected. In order to be able to evaluate which measuring instruments are best suited, an intensive literature research must be carried out in order to check which measuring instruments have been used with which results for comparable research questions. Basically, the use of questionnaires or registration forms is linked to the provision of documentation sheets for the subsequent data analysis. Because only that which has been precisely and completely documented beforehand can be evaluated. If data entries are still missing, there are procedures to supplement them in the statistically permissible sense.

In addition to the underlying study design, the choice of suitable measuring instruments is of decisive importance for achieving the study objective. Since the study objectives are often perceived as very special or are actually very special when new questions are raised, one often helps oneself by developing one's own questionnaire. This is advantageous in that your own questionnaire is usually a tailor-made instrument for your own study, provided you have asked the right questions. The serious disadvantage, however, is that the results can only be presented with a simple frequency evaluation, are not statistically secured and therefore only apply to the study participants in the narrower sense. With a study, however, one generally strives for more generally valid findings that can also be used in other regions or so-called "settings" (i.e. the immediate contexts in which a study is carried out).

Strictly speaking, self-developed questionnaires must therefore be validated before they can be used in a study. This procedure is often impractical for reasons of time, so that the ongoing study can be used for validation and the results of the validation process can be used for the critical discussion of the study results. The validation of questionnaires is now also offered as a service.

The validation of a questionnaire is a complex process in which certain quality criteria are checked and assessed, which can only be discussed briefly here:


Reliability describes the measurement accuracy or the reliability of the method used and thus the accuracy with which, for example, a scale measures a feature. To do this, one calculates the correlations of two measured values ​​of an identical questionnaire that was presented to the same person. There are various statistical methods for this (parallel test method, retest reliability, split-half reliability). In addition, the internal consistency of the individual questions in the questionnaire should be tested.


The validity in the strict sense of the word is the extent to which the test measures what it is intended to measure. A distinction is made between logical, external and internal validity, which are also determined with the help of statistical methods.

(see also http://www.online-fragebogen.com/9/fragebogen-qualitaetslösungen.html, http://www.uni-leipzig.de/~emkf/Referate/G%C3%BCtelösungen%20PPT.pdf)

Not least because of the time-consuming validation process, it is therefore advisable to use an already validated questionnaire wherever possible. However, it must first be clarified whether this is available for general use. You can find it on the Internet without any restrictions on use

are noted, it can be assumed that this is the case. In the case of commercially offered questionnaires, this question is clarified in that the terms of use are acquired by paying the stated price. In addition, manuals for the correct evaluation of the questionnaires are usually also provided here. If you are not sure, the author of a questionnaire should be identified as far as possible. In addition, as with all scientific papers, the source must be given.