workshop_best_evaluation Class Reference

Defines the computation login of the grading evaluation subplugin. More...

Inheritance diagram for workshop_best_evaluation:

Public Member Functions
	__construct (workshop $workshop)
	Constructor.
	get_settings_form (moodle_url $actionurl=null)
	Returns an instance of the form to provide evaluation settings.
	update_grading_grades (stdclass $settings, $restrict=null)
	Calculates the grades for assessment and updates 'gradinggrade' fields in 'workshop_assessments' table.
	update_grading_grades (stdClass $settings, $restrict=null)
	Calculates grades for assessment and updates 'gradinggrade' fields in 'workshop_assessments' table.

Static Public Member Functions
static	delete_instance ($workshopid)
	Delete all data related to a given workshop module instance.

Protected Member Functions
	assessments_distance (stdclass $assessment, stdclass $referential, array $diminfo, stdclass $settings)
	Measures the distance of the assessment from a referential one.
	average_assessment (array $assessments)
	Given a set of a submission's assessments, returns a hypothetical average assessment.
	normalize_grades (array $assessments, array $diminfo)
	Normalizes the dimension grades to the interval 0.00000 - 100.00000.
	prepare_data_from_recordset ($assessments)
	Prepares a structure of assessments and given grades.
	process_assessments (array $assessments, array $diminfo, stdclass $settings)
	Given a list of all assessments of a single submission, updates the grading grades in database.
	weighted_variance (array $assessments)
	Given a set of a submission's assessments, returns standard deviations of all their dimensions.

Protected Attributes
the	$settings
	recently used settings in this workshop
workshop	$workshop
	the parent workshop instance

Detailed Description

Defines the computation login of the grading evaluation subplugin.

Constructor & Destructor Documentation

__construct()

workshop_best_evaluation::__construct

(

workshop

$workshop

)

Constructor.

Parameters

workshop

$workshop

The workshop api instance

Return values

void

Member Function Documentation

assessments_distance()

workshop_best_evaluation::assessments_distance ( stdclass $assessment, stdclass $referential, array $diminfo, stdclass $settings )

protected

Measures the distance of the assessment from a referential one.

The passed data structures must contain ->dimgrades property. The referential assessment is supposed to be close to the average assessment. All dimension grades are supposed to be normalized to the interval 0 - 100. Returned value is rounded to 4 valid decimals to prevent some rounding issues - see the unit test for an example.

Parameters

stdClass	$assessment	the assessment being measured
stdClass	$referential	assessment
array	$diminfo	of stdclass(->weight ->min ->max ->variance) indexed by dimension id
stdClass	$settings

Return values

float|null

rounded to 4 valid decimals

average_assessment()

workshop_best_evaluation::average_assessment ( array $assessments )

protected

Given a set of a submission's assessments, returns a hypothetical average assessment.

The passed structure must be array of assessments objects with ->weight and ->dimgrades properties. Returns null if all passed assessments have zero weight as there is nothing to choose from then.

Parameters

array

$assessments

as prepared by self::prepare_data_from_recordset()

Return values

null|stdClass

delete_instance()

static workshop_best_evaluation::delete_instance ( $workshopid )

static

Delete all data related to a given workshop module instance.

See also

workshop_delete_instance()

Parameters

int

$workshopid

id of the workshop module instance being deleted

Return values

void

Reimplemented from workshop_evaluation.

get_settings_form()

workshop_best_evaluation::get_settings_form

(

moodle_url

$actionurl = null

)

Returns an instance of the form to provide evaluation settings.

Return values

workshop_best_evaluation_settings_form

Reimplemented from workshop_evaluation.

normalize_grades()

workshop_best_evaluation::normalize_grades ( array $assessments, array $diminfo )

protected

Normalizes the dimension grades to the interval 0.00000 - 100.00000.

Note: this heavily relies on PHP5 way of handling references in array of stdclasses. Hopefully it will not change again soon.

Parameters

array

$assessments

of stdclass as returned by {

See also

self\prepare_data_from_recordset()}

Parameters

array

$diminfo

of stdclass

Return values

array

of stdclass with the same structure as $assessments

prepare_data_from_recordset()

workshop_best_evaluation::prepare_data_from_recordset ( $assessments )

protected

Prepares a structure of assessments and given grades.

Parameters

array

$assessments

batch of recordset items as returned by the grading strategy

Return values

array

process_assessments()

workshop_best_evaluation::process_assessments ( array $assessments, array $diminfo, stdclass $settings )

protected

Given a list of all assessments of a single submission, updates the grading grades in database.

Parameters

array	$assessments	of stdclass (->assessmentid ->assessmentweight ->reviewerid ->gradinggrade ->submissionid ->dimensionid ->grade)
array	$diminfo	of stdclass (->id ->weight ->max ->min)
	stdClass	grading evaluation settings

Return values

void

update_grading_grades() [1/2]

workshop_best_evaluation::update_grading_grades	(	stdclass	$settings,
			$restrict = null )

Calculates the grades for assessment and updates 'gradinggrade' fields in 'workshop_assessments' table.

This function relies on the grading strategy subplugin providing get_assessments_recordset() method. {

See also

self\process_assessments()} for the required structure of the recordset.

Parameters

stdClass	$settings	The settings for this round of evaluation
null | int | array	$restrict	If null, update all reviewers, otherwise update just grades for the given reviewers(s)

Return values

void

update_grading_grades() [2/2]

workshop_evaluation::update_grading_grades ( stdClass $settings, $restrict = null )

abstractinherited

Calculates grades for assessment and updates 'gradinggrade' fields in 'workshop_assessments' table.

Parameters

stdClass	$settings	settings for this round of evaluation
null | int | array	$restrict	if null, update all reviewers, otherwise update just grades for the given reviewers(s)

weighted_variance()

workshop_best_evaluation::weighted_variance ( array $assessments )

protected

Given a set of a submission's assessments, returns standard deviations of all their dimensions.

The passed structure must be array of assessments objects with at least ->weight and ->dimgrades properties. This implementation uses weighted incremental algorithm as suggested in "D. H. D. West (1979). Communications of the ACM, 22, 9, 532-535: Updating Mean and Variance Estimates: An Improved Method"

Parameters

array

$assessments

as prepared by self::prepare_data_from_recordset()

Return values

null|array

indexed by dimension id

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The documentation for this class was generated from the following file:

• mod/workshop/eval/best/lib.php