Currently in GSIM:
Instrument
Definition: A tool conceived to record the information that will be obtained from the Observation Units (p. 151).
Explanatory Text: The Instrument descirbes the tool used to collect data. It could be a traditional survey, a set of requirements for a software collection program, a clinical procedure, etc.
Instrument Implementation
Definition: A concrete and usable tool for gathering information based on the rendering of the description made by an Instrument (p. 153).
Explanatory Text: This represents an implementation of an Instrument. It describes the way in which an Instrument has been translated from a design to a concrete tool. It could represent a printed form, a software program made following a specific technological paradigm (web service, web scraping robot, etc), the software used by a specialised device to collect data, etc. When it describes a Survey Instrument, it can contain descriptions of how each construct (e.g. Questions, Value Domains, validation Rules contained in the Instrument) is implemented.
Issue:
At first glance, the definitions of Instrument and Instrument Implementation are confusing because they both refer to tools - one for recording information and another for gathering information. It is difficult to understand the difference between the two objects as the exxamples in the Explanatory text are similar.
Suggested Solution:
An alternate defintion and explanatory text for Instrument:
Instrument
Definition: A means conceived to gather the information that will be obtained from the observation units.
Explanatory Text: The Instrument describes the means used to collect data. It could be a traditional survey, a set of requirements to be met by a software collection program, or a clinical procedure, etc.
The specification of an Instrument is "implementation independent". In other words, it does not depend on the way(s) in which the Instrument will be rendered (eg on paper or via software) to become a usable tool for gathering information.
Recommendation:
The definition of Instrument and Instrument Implementation could be amended (see suggested solution) to include the fact that an Instrument is format and platform independent, whereas Instrument Implementation is when an Instrument is put into a particular format.
2 Comments
user-8e470
Discussion 2/10:
Instrument and instrument implementation are at different levels - conceptual/logical and implementation.
Instrument control is at the logical level....but the instrument controls are effected by the mode? The table in the document tried to explain that it is not possible to have both an instrument and instrument implementation. It is building in flexibility that may not be possible. Action: fix the table....
The experience of filling in a paper vs web may be very different but the logical basis may be the same. There is quite a debate about whether this is possible is one that is going on in stats agencies.
Action: Change definition. Better explanatory text around this.
Action: Rename instrument implementation to represented instrument. It has the advantage of linguistic consistency.
Dick Woensdregt
The problem with Instrument and InstrumentImplementation is that an instrument is something that is either hidden in a Channel (a questionnaire on a computer used by the CAPI or CATI interviewer but never seen by the respondent) or part of the Mode (in the CAWI and self-administered PAPI). It is very implementation dependent and therefore we are argueing that perhaps Instrument should not be part of GSIM at all.