update doc

Author: shawnm0705

src/features/2.metrics.md

@@ -11,7 +11,7 @@ Metric is used to allow admin configuring custom metrics for an assessment to se
 * `description` the description of this metric
 * `is_public` whether this is a public metrics in the metrics library
 * `data_source` : which data source we are linking to for the calculation
-  * For MVP, we only support `question`
+  * For MVP, we only support `assessment question`
 * `data_type` defines how to link to an assessment question. It has the following valid value (MVP):
   * `scalar` : can only be linked to a radio button choice question of an assessment
 * `aggregation` defines how to calculate the result. It has the following valid value: (when the `data_type` is `scalar`)
@@ -44,9 +44,9 @@ Relationship between a metric and an institution
 Relationship between a metric and a data source link in an experience
 
 * `id`
-* `metrics_id`
+* `metric_id`
 * `data_source_id` : the related data source id
-  * When `data_source` = `question`, this id is the question id
+  * When `data_source` = `assessment question`, this id is the question id
 * `experience_id`
 * `institution_id`
 * `calculation_frequency` : when to calculate the metrics
@@ -57,7 +57,7 @@ Relationship between a metric and a data source link in an experience
 The table to store the metric report records
 
 * `id`
-* `metrics_question_id`
+* `metric_link_id`
 * `value` : metric data value result
 * `count` : how many data have we gone through to do the calculation
 * `created` : date when the record gets calculated