2.7 Relationships among Analytical Properties
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properties (see Fig. 2.1). At the next level down the ranking are basic properties
(precision, sensitivity, selectivity and proper sampling), which sustain capital
properties and characterize the analytical process in conjunction with accessory
properties (expeditiousness, cost-effectiveness and personnel-related factors,
which are at the lowest level in the ranking). However, this situation is only
consistent with a theoretical, basic approach since, as shown below, the analytical problem often requires quality compromises to be made that may even
reverse this theoretical hierarchy.
2.7.2 Foundation Relationships
As noted above, basic properties provide support for capital properties. A
method cannot be accurate if it is not precise (i. e. subject to little uncertainty),
sensitive and selective enough. With poor precision, sensitivity and selectivity,
the results depart markedly from the value held as true. Similarly, no representativeness can be expected unless sampling is conducted properly and
consistently with the analytical problem addressed.
Productivity is an indirect analytical feature common to other applied
disciplines that is sustained by the three accessory analytical properties (expeditiousness, cost-effectiveness and personnel-related factors) . Maximizing
productivity entails ensuring that the analytical process is expeditious, costeffective, safe and convenient to perform.
I 2.7.3 Contradictory Relationships
The two tetrahedra in Fig. 2.15 are essentially intended to facilitate the visualization of contradictory relationships among analytical properties. Their edges
represent "stress" between vertices. In each case, the tetrahedra are distorted in
a way dependent on the property or properties that are favoured over the rest in
accordance with the quality compromises adopted in addressing the analytical
problem. Some relevant examples are commented on below.
Relationship between accuracy and productivity
Overall, basic and accessory analytical properties bear a contradictory relationship via the two properties that sustain them. As can be seen from Fig. 2.16,
the two tetrahedra in Fig. 2.15 can exist in a balanced situation (where the
maximum possible accuracy and productivity are obtained through a mutual
sacrifice) or in distorted form (one tetrahedron grows at the expense of the other
when, for example, the analytical problem demands a high accuracy - and the
theoretical quality of the results prevails - or productivity). A high accuracy -
and low uncertainty - cannot be achieved without some sacrifice in productivity
- the analytical process is slower or more expensive, or involves more staff
members. If, on the other hand, productivity is to be favoured, high accuracy and
low uncertainty will be two elusive goals.
77
properties (see Fig. 2.1). At the next level down the ranking are basic properties
(precision, sensitivity, selectivity and proper sampling), which sustain capital
properties and characterize the analytical process in conjunction with accessory
properties (expeditiousness, cost-effectiveness and personnel-related factors,
which are at the lowest level in the ranking). However, this situation is only
consistent with a theoretical, basic approach since, as shown below, the analytical problem often requires quality compromises to be made that may even
reverse this theoretical hierarchy.
2.7.2 Foundation Relationships
As noted above, basic properties provide support for capital properties. A
method cannot be accurate if it is not precise (i. e. subject to little uncertainty),
sensitive and selective enough. With poor precision, sensitivity and selectivity,
the results depart markedly from the value held as true. Similarly, no representativeness can be expected unless sampling is conducted properly and
consistently with the analytical problem addressed.
Productivity is an indirect analytical feature common to other applied
disciplines that is sustained by the three accessory analytical properties (expeditiousness, cost-effectiveness and personnel-related factors) . Maximizing
productivity entails ensuring that the analytical process is expeditious, costeffective, safe and convenient to perform.
I 2.7.3 Contradictory Relationships
The two tetrahedra in Fig. 2.15 are essentially intended to facilitate the visualization of contradictory relationships among analytical properties. Their edges
represent "stress" between vertices. In each case, the tetrahedra are distorted in
a way dependent on the property or properties that are favoured over the rest in
accordance with the quality compromises adopted in addressing the analytical
problem. Some relevant examples are commented on below.
Relationship between accuracy and productivity
Overall, basic and accessory analytical properties bear a contradictory relationship via the two properties that sustain them. As can be seen from Fig. 2.16,
the two tetrahedra in Fig. 2.15 can exist in a balanced situation (where the
maximum possible accuracy and productivity are obtained through a mutual
sacrifice) or in distorted form (one tetrahedron grows at the expense of the other
when, for example, the analytical problem demands a high accuracy - and the
theoretical quality of the results prevails - or productivity). A high accuracy -
and low uncertainty - cannot be achieved without some sacrifice in productivity
- the analytical process is slower or more expensive, or involves more staff
members. If, on the other hand, productivity is to be favoured, high accuracy and
low uncertainty will be two elusive goals.