63
• and the average length of the traceability chains (corresponding to the average
shortest path length between nodes) is also small, and therefore the system is
effective because each calibration reduces the quality of the provided information, so that minimizing the length of a traceability chain maximizes the quality
of the measurement results.
Hence the metrological system reproduces the structure of a small-world network,
which at the same time is connected but guarantees a small number of degrees of
separation (Watts & Strogatz, 1998).
In the case of reading comprehension ability (like most other psychosocial properties), without direct reference objects, the same system of reference properties
does not pertain. However, responses to test questions are informational, and hence,
if they are seen as stand-in reference objects, then a similar system can be constructed, using comparisons between the scored responses to the questions in the
original sample and a second sample of responses (Wilson, 2013). Just as in the
discussion above, the length of the traceability chain can be kept relatively short by
always using the original sample to calibrate new sample sets. A logic built in this
way can be seen as a parallel to the traditional concept of a measurement system
(Maul, Mari, & Wilson, 2019).
3.3.2 The measurement environment
As presented in Chap. 2, a measurement result reported as the Basic Evaluation
Equation
Q a x
> @ q ref
assumes that, on the one hand, the (direct or indirect) comparison between the measurand Q[a] and the unit q ref depends only on these two quantities. On the other
hand, in real-world contexts the comparison may be affected by influence properties, of the object under measurement or the environment: if an influence property
changes, the measurement result could also change even if the measurand remains
the same.
For example, returning to an example we used above, the length of a rigid body
could be measured by a caliper whose structure is sensitive to the environmental
temperature in such a way that different indications are obtained for the same measurand when the temperature changes: in this case, then, environmental temperature
is an influence property. In the case of the measurement of reading comprehension
ability, an influence property might be the specific content of the passages a person
reads: a person with strong prior knowledge of the content may be more likely to
successfully answer related questions than someone less familiar with the content,
even though they may have the same reading comprehension ability.
3.3 The operational context
• and the average length of the traceability chains (corresponding to the average
shortest path length between nodes) is also small, and therefore the system is
effective because each calibration reduces the quality of the provided information, so that minimizing the length of a traceability chain maximizes the quality
of the measurement results.
Hence the metrological system reproduces the structure of a small-world network,
which at the same time is connected but guarantees a small number of degrees of
separation (Watts & Strogatz, 1998).
In the case of reading comprehension ability (like most other psychosocial properties), without direct reference objects, the same system of reference properties
does not pertain. However, responses to test questions are informational, and hence,
if they are seen as stand-in reference objects, then a similar system can be constructed, using comparisons between the scored responses to the questions in the
original sample and a second sample of responses (Wilson, 2013). Just as in the
discussion above, the length of the traceability chain can be kept relatively short by
always using the original sample to calibrate new sample sets. A logic built in this
way can be seen as a parallel to the traditional concept of a measurement system
(Maul, Mari, & Wilson, 2019).
3.3.2 The measurement environment
As presented in Chap. 2, a measurement result reported as the Basic Evaluation
Equation
Q a x
> @ q ref
assumes that, on the one hand, the (direct or indirect) comparison between the measurand Q[a] and the unit q ref depends only on these two quantities. On the other
hand, in real-world contexts the comparison may be affected by influence properties, of the object under measurement or the environment: if an influence property
changes, the measurement result could also change even if the measurand remains
the same.
For example, returning to an example we used above, the length of a rigid body
could be measured by a caliper whose structure is sensitive to the environmental
temperature in such a way that different indications are obtained for the same measurand when the temperature changes: in this case, then, environmental temperature
is an influence property. In the case of the measurement of reading comprehension
ability, an influence property might be the specific content of the passages a person
reads: a person with strong prior knowledge of the content may be more likely to
successfully answer related questions than someone less familiar with the content,
even though they may have the same reading comprehension ability.
3.3 The operational context