Index: openacs-4/packages/assessment/www/doc/data_collection.html =================================================================== RCS file: /usr/local/cvsroot/openacs-4/packages/assessment/www/doc/data_collection.html,v diff -u -r1.6 -r1.7 --- openacs-4/packages/assessment/www/doc/data_collection.html 4 Aug 2004 19:52:41 -0000 1.6 +++ openacs-4/packages/assessment/www/doc/data_collection.html 5 Aug 2004 01:29:06 -0000 1.7 @@ -109,38 +109,25 @@ procedurally sign all as_item_data at once if the assessment author requires only a section-level or assessment-level signature.

+
  • "Events" related to assessments In some applications (like clinical trials), it is important to define + a series of "named" assessment events (like "baseline" "one month" "six months" etc) at which time assessments + are to be performed. Earlier we included an "event_id" attribute in data collection entities (notably as_item_data) + to make mapping of these events to their data easy. This denormalization makes some sense for efficiency considerations, + but it doesn't prove to be generally applicable enough to most contexts, so we've removed it. Instead, any + client package using Assessment in this fashion should implement its own relationships (presumably with acs_rels).

    • +
  • "Status" of data collection entities An assessment author may specify different allowable steps + for her assessment -- such as whether a user can "save&resume" between sessions, whether a second user needs + to "review&confirm" entered data before it becomes "final", etc etc. Rather than try to anticipate these kinds + of workflow options (and considering that many uses of Assessment won't want to track any such status), we've + decided to move this out of the data model for Assessment per se and into Workflow. Assessment authors will have + a UI through which they can configure an applicable workflow (defining states, roles, actions) for the assessment.
    • -

    While this doesn't impact the datamodel structure of this data collection subsystem per se, we do add an - important innovation to Assessment that wasn't used in "complex survey" or - questionnaire. When a user initiates an Assessment Session (either by requesting the assessment form - to complete herself -- such as in an online survey -- or by an admin user "assigning" the assessment to be - performed by -- or about -- a subject at some point in the future), an entire set of - Assessment data collection objects is created (literally, rows are inserted into all the - relevant tables -- as_section_data, as_item_data). Since these are CR-based entities, this means that - a cr_item and the initial cr_revision record are created for each of these entities. Then when - the user submits a form containing responses to one or more items in the assessment, the database - action consists of updates in the CR, not insertions. This contrasts to the existing "survey" packages, - in which "survey_response" or "survey_question_response" rows are only inserted once the user submits - the html form.

    -

    Why is this a good idea? Here's the use case: for an educational course, a teacher plans a set of six - exams that the students can complete at their own rate. The teacher wants Assessment to tell her at any - moment the status -- at the individual item level -- the status of each student's progress through the exam - series. In fact, the UI to do this should create a grid consisting of columns corresponding to the exams (and - the individual exam questions in a drill-down) and rows consisting of each student. Each cell in this grid - will be colored red if the item is unanswered, yellow if answered but not "confirmed" (ie the student has "saved&resumed" - the exam and wants to revise it further), and green if "confirmed" ie "handed in".

    -

    If the data collection subsystem doesn't create a set of "empty" records, the only way that procedurally this - kind of report can be generated is by repeatedly looping through the assessment's metadata and looking for the - existence or nonexistence of corresponding records in the data collection entities for each of the students. This - is the way the current survey and questionnaire packages have had to do it; it is ugly, error prone, and inefficient. - We need to do it differently in Assessment!

    Synopsis of Data-Collection Datamodel

    Here's the schema for this subsystem:

    -
    Source Graffle file +

    Data Model

    @@ -173,8 +160,6 @@ style="color: rgb(255, 0, 0);">
  • staff_id - references Users if someone is doing the Assessment as a proxy for the real subject
    • -
  • event_id - this is a foreign key to the "event" during which this assessment is - being performed -- eg "second term final" or "six-month follow-up visit" or "Q3 report".
  • target_datetime - when the subject should do the Assessment
  • creation_datetime - when the subject initiated the Assessment
    • @@ -183,8 +168,6 @@
  • last_mod_datetime - the most recent submission
  • completed_datetime - when the final submission produced a complete Assessment
    • -
  • session_status - Status of the session (and therefore of the - assessment with regards to the subject)
  • ip_address - IP Address of the entry
  • percent_score - Current percentage of the subject achieved so @@ -210,9 +193,6 @@
  • section_id
  • subject_id
  • staff_id
    • -
  • event_id - this is a foreign key to the "event" during which this assessment is - being performed -- eg "second term final" or "six-month follow-up visit" or "Q3 report".
    • -
  • section_status

    • @@ -233,17 +213,6 @@
  • subject_id
  • staff_id
  • item_id
    • -
  • item_status - Status of the answer; defaults to "unanswered". Other options could include - "submitted, deferred, confirmed, final, is_unknown" -- but this shouldn't be hard-wired into the sql but - rather be something that can be configured via categories. Note that this single field - can replace the previous "is_unknown_p" field which we previously added. - This field is important to clearly - distinguish an Item value that is unanswered from a value that means - "We've looked for this answer and it doesn't exist" or "I don't know - the answer to this". Put another way, if none of the other "value" - attributes in this table have values, did the subject just decline to - answer it? Or is the "answer" actually this: "there is no answer". This - attribute toggles that clearly when set to "is_unknown".
  • choice_id_answer - references as_item_choices
  • boolean_answer
  • numeric_answer