RFC 1431 (rfc1431) - Page 2 of 19

DUA Metrics (OSI-DS 33 (v2))

RFC 1431                      DUA Metrics                  February 1993


   8.  Strategy for locating entries...........................       9
   9.  Displaying results......................................      10
   10. Association Handling....................................      11
   11. Suitability for management..............................      12
   12. Query Resolution........................................      13
   13. International Languages.................................      16
   14. User Friendliness.......................................      16
   15. Operational Use.........................................      17
   16. Security Considerations.................................      19
   17. Author's Address........................................      19

1.  Overview

   The purpose of this document is to define some metrics by which DUA
   products can be measured.  It should be first be noted that the use
   of the term "DUA" is rather misleading.  There is an assumption here
   that the DUA is implemented correctly and is able to "talk" valid
   X.500 protocol: this is a sine qua non.  Instead, this document seeks
   to draw out the characteristics of Directory user interfaces.
   However, the term DUA is persisted with as it is used by most people
   when referring to Directory user interfaces.  The format of these DUA
   metrics is essentially a questionnaire which extracts a detailed
   description of a user interface.  DUAs come in very different forms.
   Many make use of windowing environments, offering a "high-tech" view
   of the Directory, while others are designed to work in a terminal
   environment.  Some interfaces offer extensive control over the
   Directory, and thus may be well-suited to Directory managers, while
   others are aimed more at the novice user.  Some interfaces are
   configurable to allow searches for any attribute in any part of the
   DIT, while others lack this generality but are focussed on handling
   the most typical queries well.  In many aspects, it is almost
   impossible to say that one DUA is better than other from looking at
   the responses to question in this document.  A flexible management
   tool will be better for management than a DUA aimed at servicing
   simple look-ups, and vice-versa.  Furthermore, in other areas, there
   are several radically different approaches to a problem, but it is
   not as yet clear whether one approach is better than another.  One
   example of this is the extent to which a DUA provides an abstraction
   of the underlying DIT hierarchy, either emphasising the world as a
   tree or trying to conceal this from the user.

   However, other aspects, such as whether the DUA can actually find the
   entries required, and if so, how quickly, can be directly measured in
   some way.  Throughout this document, some of the questions posed are
   annotated with a square-bracketed points score and an explanation as
   to how the points should be allocated.  For example, a question might
   be appended with "[2 if yes]", indicating score 2 points for an
   affirmative answer to that question.  These points scores should be



Barker