21        Comparing and evaluating drawings

Taeke De Jong


21.1    Explicitness and expressiveness.......................... 1

21.2    Comparability.......................................................... 1

21.3    Documentation and retrievability............................ 1

21.4    Supposed context and perspective....................... 1

21.5    Intended and not intended effects......................... 2

21.6    Effect analysis....................................................... 2

21.7    Evaluation............................................................... 2

21.8    Judging drawings.................................................. 3


Design study, design research and study by design imply already by themselves comparison of different designs or designs in a different stage. Also when considers judging a design ‘on its own merit’ one employs implicit references. With a scientific design they should be explicit. In design research the designs should be studied empirically (goal-orientated or means-orientated). In design study and study by design they are made. Judging them (with norms) supposes evaluating them (with values). Evaluating supposes effect analysis (without values), and effect analysis supposes comparing; by identifying differences and comparing supposes explicit and expressive description. This Chapter provides criteria for these levels of evaluation.


21.1       Explicitness and expressiveness

When one plan is more pronounced and eloquent than another (more explicit and unequivocal to understand) it is impossible for the judging agency to compare and, therefore, to judge. Both criteria represent the information content of the drawing, its diversity and the extent to which the designer has reached statements and stimulating ideas (see page ).


A plan that is not outspoken leaves everything in vague images to the fantasy and the references of the judge. It might be poetical, evocative, productive and innovative (in practice also lucrative as a disguised study of the wishes of the principal), but it cannot be judged scientifically in principle. ‘Outspokenness’ is a condition for each following criterion. With a means-orientated design sketches lacking that quality may be the object of consideration on its way to an outspoken design.


Next, a design may be outspoken, but lacking richness; e. g. it may comprise only clichés and by the same token not say more than what everybody knew already, even if it is visualised in a new way. This is, for instance, the case when a design would consist out of two inter-locking legend units ‘built’ and ‘unbuilt’ with the smallest boundary length between them: very outspoken, yet not always rich. With a plan like that one hears the judge sigh “What should I say about this now?” Thus, this criterion is also a condition for all subsequent criteria.


21.2       Comparability

The drawings of plans to compare should obey some criteria. Plans of a different scale and resolution are hard to compare, also since the legends are not identical per definition. In order to compare a plan with a lower level of scale to one with a higher one, the plan with a higher scale level should get the same legend (Latin: legenda: things that must be read). For that purpose one can quickly substitute in a part of the plan standard components (capacity plan). A capacity plan fills the location with the same programme as the design (interpolation) with standard components (zero variant). The design proposed may be compared with this: in which regards is it different, better or worse?


21.3       Documentation and retrievability

The outspoken and rich architectural drawing is only comparable and quotable in a scientific forum and thus open to criticism in a different scientific context, if with it such documentation is provided (key-words, possibly syntactically connected) that the drawing by itself is reducible to scale (frame and grain), site, intention, context, perspective and possible readable effects on the context. These image characteristics are as many foundations for comparison to enable scientific judgement.


21.4       Supposed context and perspective

In contexts the political, cultural, economical, technical and/or ecological-spatial context on different scale level may be involved. Not only a context with a larger scale than the frame of the design plays a rôle, but also the context with a smaller size than the grain of the design (the smallest unity in the design process).


Comparison of plans always takes place implicitly from a given perspective, an expectation with regard to probable political, cultural, economical, technical and/or ecological-spatial developments outside of the design-object. An effect analysis in one perspective may work out entirely differently in another one. In the case of the scientific design it is expected that this personal perspective is made explicit: ‘I expect a steering national authority, a following regional authority, a shrinking local economy..’, etc. These points of departure may be the same for different effect analyses.


21.5       Intended and not intended effects

After execution (ex post), a design always has many political, cultural, economical, technical and/or ecological-spatial effects. They can be intended or not intended. The intended effects have been determined beforehand as design criteria in a programme of requirements. Usually they are positive and need not be involved in effect analysis. They should be mentioned beforehand as intention, goal formulation, design criteria or design programme and play a rôle in the judgement: ‘Have the criteria been met?’ In this respect an effect analysis would only lead to circular reasoning like: ‘The goal was to realise a hundred homes; ah well, the design foresees in a hundred homes, so the effect is that a hundred homes have been realised.’ The unintended effects (e.g. ‘Because a hundred homes have been added to my design the shopping centre has become too small.’) can never been foreseen in their entirety, but should receive attention in the apology of a design (intervention).


21.6       Effect analysis

During effect analyses the effects of the differences between two outspoken and rich plans are compared. They enable evaluations based on values, but they do not equal them. They are just condition for evaluations: identical effects may be valued differently. For that reason an evaluation should be preceded by a more objective effect analysis. This criterion of an added effect report with some possible evaluations for a scientific design thus goes beyond the usual criteria for empirical-scientific study. In the apology of a design, attention is asked for the effect of each design intervention on the design itself, and on its context within a perspective.


The first step in an effect analysis is to make the plans comparable by bringing the legends of both to the most detailed level. The second and third steps are to make a summary of the differences and to select one difference in order to report the effects of that particular difference. For instance: ‘In this plan the civic centre lies more excentric than in the zero-plan.’ If one would report the effects of all differences in one sweep it is impossible to see which design intervention caused the effects precisely.


Figure 1 Steps in effect analysis comparing plans


The fact that some effects can only emerge through combination of design interventions complicates the situation. The fourth step is to select the categories undergoing the effect, the working (suffering objects)[1]: for instance political, cultural, economic, technical, ecological or spacial objects (their spreading or concentration). On which scale do the effects manifest themselves? To answer that question, see the context diagram on page . The fifth step is to consider the effects in the perspective chosen.


21.7       Evaluation

The sixth step is to determine the positive or negative effect per suffering object and to try to provide them with a numerical value. The seventh step is an evaluation: to ascribe to the suffering objects a mutual weight (for instance: the effect on an ecological object is more important than the effect on a cultural object).


The final step may be a list of effects, multiplied by their weight and a conclusion. Is the design superior to the zero variant? Also the scholar designer who reaches the conclusion that this is not the case (which could show itself in a low appreciation for the design on the appropriate scale level) may receive high scientific regard for the evaluation.


21.8       Judging drawings

Judging pre-supposes comparison as well, even if it is often implicit in who judges and in the person judged (the designer). Both parties do have their references. The judgement ‘this is a bad chair’ pre-supposes other chairs. By the same token judging requires at least two comparable plans: the design to be judged and at least one comparable ‘zero plan’ (precedent, reference, example with a comparable programme, a capacity plan[2] in a comparable context, limitation and legends). For a scientific design one such zero-plan, like intended in criterion A, page  must be explicit. If a zero-plan is known, the unintended effects this zero-plan has in common with the design to be judged are not open for discussion. If the designer would not make such a reference explicit, the discussion would be endless. Judgement would concern the immense number of thinkable differences compared to all references of the judge. A reference plan concentrates the judgement on meaningful differences. Nevertheless the judge may always introduce other references. Criticism then concentrates on the selection of the reference. The intended effects always stand to discussion as preliminarily formulated criteria.



[1]   This term has been chosen since each effect analysis has the form of a full-sentence with a subject (the design intervention at the source of the operation), a verb (working) and an object (the object undergoing the working). See also Chapter Fout! Verwijzingsbron niet gevonden. on verbal models.

[2]   For instance a collage with programmatically equivalent components from known plans.