# question_statistics

0 rows

### Description

Statistics for individual questions used in an activity.

### Columns

Column | Type | Size | Nulls | Auto | Default | Children | Parents | Comments
--- | --- | --- | --- | --- | --- | --- | --- | ---
id | BIGINT | 19 |  | √ | null |  |  |
hashcode | VARCHAR | 40 |  |  |  |  |  | sha1 hash of serialized qubaids_condition class. Unique for every combination of class name and property.
timemodified | BIGINT | 19 |  |  | null |  |  |
questionid | BIGINT | 19 |  |  | null |  |
question.id | question_statistics_erd_question_idR
slot | BIGINT | 19 | √ |  | null |  |  | The position in the quiz where this question appears
subquestion | SMALLINT | 5 |  |  | null |  |  |
variant | BIGINT | 19 | √ |  | null |  |  |
s | BIGINT | 19 |  |  | 0 |  |  |
effectiveweight | DECIMAL | 15,5 | √ |  | null |  |  |
negcovar | TINYINT | 3 |  |  | 0 |  |  |
discriminationindex | DECIMAL | 15,5 | √ |  | null |  |  |
discriminativeefficiency | DECIMAL | 15,5 | √ |  | null |  |  |
sd | DECIMAL | 15,10 | √ |  | null |  |  |
facility | DECIMAL | 15,10 | √ |  | null |  |  |
subquestions | LONGTEXT | 2147483647 | √ |  | null |  |  |
maxmark | DECIMAL | 12,7 | √ |  | null |  |  |
positions | LONGTEXT | 2147483647 | √ |  | null |  |  | positions in which this item appears. Only used for random questions.
randomguessscore | DECIMAL | 12,7 | √ |  | null |  |  | An estimate of the score a student would get by guessing randomly.

### Indexes

Constraint Name | Type | Sort | Column(s)
--- | --- | --- | ---
PRIMARY | Primary key | Asc | id
quesstat_que_ix | Performance | Asc | questionid

### Relationships