Data Profile Report

Generated on November 24, 2025 at 09:54 PM

Overview

This dataset captures granular student activity data from the OpenStax Tutor learning platform, documenting every step within assigned tasks including exercise responses, reading interactions, completion timestamps, and grading information. It enables analysis of student learning behaviors, assignment effectiveness, and educational outcomes.

Unit of Analysis

• Task Step - Each row represents a single step within a student's assignment (e.g., one exercise question, one reading section, one video). A complete assignment contains multiple steps, and each student's assignment generates separate step records.

Scope & Filters

• Temporal: Tasks created between specified date range (time1 to time2)
• Course Type: Production courses only (excludes preview courses; test courses optional via qtest parameter)
• Task Types: Includes homework (0), reading (1), external (2), event (3), practice (4), chapter practice (5), page practice (6), mixed practice (7), and concept coach (9)
• Task Plans: Excludes preview assignment templates

Key Dimensions

Student Context

• Anonymized student identifiers (research_identifier)
• Course and period enrollment information
• Student demographics (name fields for authorized use)

Assignment Structure

• Task hierarchy:
  Plan → Task → Steps
• Assignment metadata (title, type, creation date)
• Content ecosystem version tracking

Step Content

• Polymorphic step types (exercises, readings, videos, interactives)
• Content references (pages, exercises) with book location
• Exercise-specific data (questions, answers, tags)

Student Responses (for exercise steps)

• Answer submissions and correctness
• Free-response text and grading
• Response validation and feedback
• Attempt tracking

Temporal Data

• Step creation timestamps
• First and last completion times
• Assignment lifecycle tracking

Content Metadata

• Learning objective (LO) and skill tags
• Book and page references with hierarchical location
• Exercise difficulty and classification tags
• Textbook ecosystem versioning

Primary Use Cases

• Learning Analytics: Student engagement patterns, time-on-task analysis
• Content Effectiveness: Exercise difficulty calibration, content performance
• Educational Research: Learning behavior studies, intervention analysis
• Instructor Insights: Assignment completion rates, common misconceptions
• Adaptive Learning: Personalization based on performance patterns

Data Granularity

• Finest grain: Individual step within an assignment (e.g., question 3 of homework 5)
• Aggregation potential: Roll up to assignment level, student level, course level, or content level
• Temporal resolution: Precise timestamps for creation and completion events

Coverage

All student activity on non-preview assignments within the specified date range, including:

• Complete and incomplete assignments
• All step types (exercises, readings, videos, etc.)
• Graded and ungraded work
• Core and supplemental content

Technical Notes

• Generated from PostgreSQL production database via parquet file exports
• Optimized for large-scale data processing (millions of rows)
• Preserves referential integrity across related tables
• Left joins preserve steps without exercises/pages (NULL values expected)

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Executive Dashboard

🟢 Data Quality Grade: A (92/100)

Metric	Value	Status
Total Rows	27,996,816	✅
Total Columns	95	✅
Completeness	80.3%	⚠️
Columns with Issues	1	⚠️
Processing Time	90.4s	✅

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🔍 Data Quality Alerts

❌ Critical Issues

These issues require immediate attention:

• dropped_at: 98.0% null values (sparse data)
• school_district_school_id: 96.2% null values (sparse data)
• withdrawn_at: 93.7% null values (sparse data)
• title_exercise: Column is completely empty (100% null)
• grader_points: 99.9% null values (sparse data)
• grader_comments: 99.9% null values (sparse data)
• last_graded_at: 99.9% null values (sparse data)
• free_response_grade: 99.9% null values (sparse data)
• published_comments: 99.9% null values (sparse data)

⚠️ Warnings

Review these columns for potential issues:

• fragment_index: 67.2% null values (partial data)
• role_type: Only 1 unique values in 27,996,816 rows
• description: 52.4% null values (partial data)
• updated_by_instructor_at: 63.1% null values (partial data)
• title_exercise: Only 0 unique values in 27,996,816 rows
• free_response: 58.7% null values (partial data)
• answer_id: 52.0% null values (partial data)
• response_validation: 60.1% null values (partial data)
• book_location: 337 unique categories (consider if this should be text/identifier)
• course_name: 920 unique categories (consider if this should be text/identifier)
• city: 313 unique categories (consider if this should be text/identifier)
• title_1_school: Only 1 unique values in 27,996,816 rows

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📊 Column Profiles

Columns are organized by data type for easier navigation.

🔑 Identifier (28 columns)

Unique identifiers (IDs, keys, UUIDs)

Column	Data Type	Variable Type	Completeness	Unique Values	Cardinality	Sample Values	Description
tasks_task_id	INTEGER	identifier	100.0%	1,325,391	4.7%	1495846, 1640791, 2061782	Assignment identifier for a specific student
tasked_id	INTEGER	identifier	100.0%	24,886,892	88.9%	14705499, 4923798, 39417216	Unique id for a specific step for a specific assignment and specific student
tasks_task_plan_id	INTEGER	identifier	98.1%	28,019	0.1%	214112, 199873, 128501	Foreign key linking an individual student's task instance back to the instructor's original task plan (assignment template). This connects a student's specific assignment to the main plan that generated it.
course_id	DOUBLE	identifier	100.0%	1,368	0.0%	15534.0, 8142.0, 12789.0	Unique identifier for teacher-created course on OpenStax Tutor
entity_role_id	INTEGER	identifier	100.0%	54,138	0.2%	70579, 191533, 109791	Unique identifier for a user's role within the system. This is the primary key that links users to their various roles (student, teacher, etc.) and connects them to their activities across courses.
course_profile_course_id_student	INTEGER	identifier	100.0%	1,368	0.0%	3889, 10667, 16879	Course section id from course_membership_students linking the learner’s enrollment to course_profile_courses
uuid	VARCHAR	identifier	100.0%	54,138	0.2%	27741d9b-20a1-49a8-baf1-b96111f89b8d, 49fae85e-53e5-485b-8f5e-4a9e5533bfaa, c1b9e7e4-e0f6-434c-bdb2-7950932f68b3	Foreign key identifying which course this record belongs to
period_id	INTEGER	identifier	100.0%	1,725	0.0%	11951, 23255, 32965	Course-period id in which the student was enrolled
school_district_school_id	INTEGER	identifier	⚠️ 3.8%	16	0.0%	1291, 1297, 1102	Identifier for the school district for a specific OpenStax course
plan_id	INTEGER	identifier	98.1%	1,368	0.0%	8538, 7788, 8563	Unique identifier for the task plan that generated this task. A task plan is the instructor's assignment template/blueprint that defines what content should be assigned, to which students, and when.
tasks_grading_template_id	INTEGER	identifier	98.1%	2,686	0.0%	25525, 10008, 9658	Teacher created grading template
exercise_id	INTEGER	identifier	59.4%	139,456	0.8%	544259, 585359, 333322	tasks_tasked_exercises.content_exercise_id , the canonical question record in content_exercises used for the step
answer_id	VARCHAR	identifier	⚠️ 48.0%	185,631	1.4%	393425, 316849, 371854	Index of the correct response
correct_answer_id	VARCHAR	identifier	59.1%	55,496	0.3%	368103, 381186, 596529	Index of the correct response
question_id	VARCHAR	identifier	59.4%	57,355	0.3%	94083, 96743, 147007	Internal numeric identifier for questions
uuid_exercise	VARCHAR	identifier	59.4%	16,642,469	100.0%	3aa054c8-24fb-4ea3-8acc-645d75a569c2, d5c46ded-fdfd-469e-b534-4eedbda9c7cb, efc2674c-fad7-48e5-afc9-31ca35d26b4f	Internal unique identifier for exercises
period_uuid	VARCHAR	identifier	100.0%	1,725	0.0%	a85fcd18-de0d-4ba0-b6ee-024b189f158e, 1c4c4018-16a8-4695-b826-0254d8a74a8b, 350c48f6-8063-4193-a750-5d1af43bf2c5	Internal unique identifier for course periods created on OpenStax Tutor
course_uuid	VARCHAR	identifier	99.2%	1,360	0.0%	fe9c820c-1816-4564-b46c-6a3f3cdee2cd, dfd8ce33-f709-4f85-bea0-8ac27a7e1f1f, 44b48e09-cb5a-4dee-85ed-3053b29caba7	Internal unique identifier for courses created on OpenStax Tutor

📑 Categorical (24 columns)

Categorical variables with limited distinct values

Column	Data Type	Variable Type	Completeness	Unique Values	Cardinality	Sample Values	Description
tasked_type	VARCHAR	categorical	100.0%	6	0.0%	Reading, Placeholder, Video, Interactive, Exercise ... (6 total levels)	Type of activity for the assignment step
group_type	VARCHAR	categorical	100.0%	3	0.0%	core, personalized, spaced_practice	Type of intervention/formative assessment
labels	VARCHAR	categorical	100.0%	9	0.0%	["review"], [], ["phet-explorations"], ["example"], ["interactive"] ... (9 total levels)	Type of activity as indicated by the book processing instructions
fragment_index	INTEGER	categorical	⚠️ 32.8%	21	0.0%	2, 3, 4, 8, 7 ... (21 total levels)	Tutor assignment splits the page into fragments and the index denotes which fragment the step is associated with
task_type	VARCHAR	categorical	100.0%	5	0.0%	homework, page_practice, practice_worst_topics, reading	The type of assignment
term	INTEGER	categorical	100.0%	4	0.0%	4, 3, 5, 2	Academic semester, 2 = Spring, 3 = Summer, 4 = Fall, 5 = Winter
year	INTEGER	categorical	100.0%	7	0.0%	2021, 2023, 2024, 2022, 2019 ... (7 total levels)	Calendar year
wrq_count	INTEGER	categorical	98.1%	26	0.0%	0, 12, 7, 5, 6 ... (26 total levels)	Written response question count
question_index	INTEGER	categorical	59.4%	8	0.0%	2, 0, 1 ... (8 total levels)	Multi-part question index, few questions of this type existed
attempt_number	INTEGER	categorical	59.4%	9	0.0%	0, 2, 1 ... (9 total levels)	How many times a student responds to an assignment step. NA corresponds to reading assignments, 0 is the default when an exercise is assigned but not completed. When a student completes the exercise, attempt number increases by 1 with every time that it is attempted.
book_location	VARCHAR	categorical	96.6%	337	0.0%	[44,1], [4,4], [29,1], [29,4], [27,9] ... (337 total levels)	Chapter, section of OpenStax textbook
book_title	VARCHAR	categorical	96.6%	11	0.0%	College Physics for AP® Courses, Anatomy and Physiology, U.S. History, Biology for AP® Courses, Biology ... (11 total levels)	Name of the book
book_version	VARCHAR	categorical	96.6%	52	0.0%	8.12, 15.1, 6.202, 7.3, 4.2 ... (52 total levels)	Version of the book
step_type	VARCHAR	categorical	100.0%	6	0.0%	exercise, reading, interactive, placeholder, video ... (6 total levels)	Type of the part of the assignment
course_start_date	VARCHAR	categorical	99.2%	26	0.0%	1/1/18, 5/1/18, 1/1/23, 4/1/23, 1/1/24 ... (26 total levels)	When the course starts
book_name	VARCHAR	categorical	99.2%	9	0.0%	AP Physics, US History, College Physics (Algebra), Psychology, Biology ... (9 total levels)	Book Name
course_name	VARCHAR	categorical	99.2%	920	0.0%	Elements of Physics I, Introductory Physics II, Biology 182, PHYS 1112 Introductory Physics 2, Elements of Physics II section 11 ... (920 total levels)	Instrutor assigned name of course
school_type	VARCHAR	categorical	99.2%	6	0.0%	K-12 School, High School, College/University (4), Technical/Community College (2), Home School ... (6 total levels)	Type of institution, comes from our business data and are verified to the best of our knowledge
city	VARCHAR	categorical	99.2%	313	0.0%	Glenside, Chalmette, Espanola, Bluffton, San Francisco ... (313 total levels)	City of use
state_province	VARCHAR	categorical	99.1%	51	0.0%	California, North Carolina, Iowa, Wisconsin, Kentucky ... (51 total levels)	State of use
country	VARCHAR	categorical	99.2%	2	0.0%	United States, United States Territory	Country of use

📈 Continuous (5 columns)

Continuous numeric variables (decimals, floats)

Column	Data Type	Variable Type	Completeness	Unique Values	Min	Max	Mean	Sample Values	Description
grader_points	DOUBLE	continuous	⚠️ 0.1%	59	0	12	1.66	1.0, 2.0	Instructor/Teaching Assistant assigned points for each assignment step but may not be published
free_response_grade	DOUBLE	continuous	⚠️ 0.1%	54	0	12	1.7		Grader points when published

🔢 Discrete (4 columns)

Discrete numeric variables (integers, counts)

Column	Data Type	Variable Type	Completeness	Unique Values	Min	Max	Mean	Sample Values	Description
role_type	INTEGER	discrete	100.0%	1	3	3	3	3	Number that corresponds to 2 = instructor, 3 = students, 4 = teacher viewing as student
ungraded_step_count	INTEGER	discrete	98.1%	93	0	341	0.64	13, 38, 0	Number of assignment steps that are left to be manually graded
gradable_step_count	INTEGER	discrete	98.1%	178	0	727	2.06	32, 23, 64	Total number of assignment steps that are eligible to be manually graded

☑️ Boolean (6 columns)

Boolean variables (true/false)

Column	Data Type	Variable Type	Completeness	Unique Values	Cardinality	Sample Values	Description
is_core	BOOLEAN	boolean	100.0%	2	0.0%	true, false	Any steps that an instructor selected as core, as well as questions at the end of reading, that all students enrolled in the course had to complete
is_preview	BOOLEAN	boolean	100.0%	1	0.0%	false	The course/assignment is for preview
is_test	BOOLEAN	boolean	100.0%	1	0.0%	false	It is a test course
is_college	BOOLEAN	boolean	77.9%	2	0.0%	true, false	If it is a college course
is_preview_plan	BOOLEAN	boolean	98.1%	1	0.0%	false	If assignment is for preview
is_in_multipart	BOOLEAN	boolean	59.4%	2	0.0%	false, true	If the question is part of a multi-part

📅 Datetime (22 columns)

Date and time columns

Column	Data Type	Variable Type	Completeness	Unique Values	Cardinality	Sample Values	Description
first_completed_at	VARCHAR	datetime	68.5%	19,187,762	100.0%	2021-10-03 18:44:10.275544, 2021-09-08 03:03:32.871312, 2019-02-20 20:40:24.434679	Timestamp from tasks_task_steps.first_completed_at capturing when the step was first finished by the student
last_completed_at	VARCHAR	datetime	68.5%	19,187,770	100.0%	2018-10-26 01:27:23.855325, 2019-04-15 19:07:12.109664, 2018-11-06 06:24:48.643782	tasks_task_steps.last_completed_at , i.e., the most recent completion time for the step
created_at	VARCHAR	datetime	100.0%	986,532	3.5%	2023-03-24 00:54:36.306526, 2022-01-23 21:24:00.93717, 2021-01-25 18:17:16.641405	Row creation time for the step record ( tasks_task_steps.created_at )
updated_at	VARCHAR	datetime	100.0%	19,663,182	70.2%	2021-09-29 02:12:37.022564, 2019-01-24 22:05:25.188974, 2021-10-28 02:10:51.110241	Last update timestamp for the step row ( tasks_task_steps.updated_at )
created_at_task	TIMESTAMP WITH TIME ZONE	datetime	100.0%	621,940	2.2%	2022-09-15 03:30:52.468544+00, 2021-10-28 01:42:06.328193+00, 2019-09-24 17:36:19.947157+00	Parent assignment creation time from tasks_tasks.created_at
created_at_role	VARCHAR	datetime	100.0%	54,138	0.2%	2020-02-02 13:04:16.631878, 2021-02-05 17:23:39.246093, 2021-01-25 08:04:16.53745	Timestamp when the learner’s entity_roles record was inserted
updated_at_role	VARCHAR	datetime	100.0%	54,138	0.2%	2021-08-30 22:53:30.280348, 2021-12-16 16:25:56.025706, 2019-05-22 13:58:35.870204	Last update time for that entity_roles row
created_at_profile	VARCHAR	datetime	100.0%	47,121	0.2%	2019-09-02 19:31:17.349562, 2021-07-05 15:13:11.590168, 2020-01-25 21:40:24.847115	Creation time for the linked OpenStax account in user_profiles.created_at
updated_at_profile	VARCHAR	datetime	100.0%	47,121	0.2%	2021-05-13 18:57:40.071454, 2020-07-06 23:58:56.751613, 2023-08-25 17:22:29.451434	When the OpenStax account profile was updated
dropped_at	VARCHAR	datetime	⚠️ 2.0%	1,516	0.3%	2019-02-05 20:55:08.849286, 2019-11-07 21:24:36.504898, 2022-09-19 15:38:11.75522	Student dropping out of course
created_at_student	VARCHAR	datetime	100.0%	54,138	0.2%	2021-06-16 15:37:58.362784, 2018-08-14 14:48:47.963283, 2019-01-09 04:18:07.495438	Timestamp when the student’s enrollment row was created in course_membership_students
updated_at_student	VARCHAR	datetime	100.0%	54,138	0.2%	2020-02-07 21:02:38.41562, 2022-01-10 18:56:04.076358, 2022-01-04 04:36:40.124625	Last modification time for that course_membership_students record
publish_last_requested_at	VARCHAR	datetime	98.1%	28,019	0.1%	2018-09-26 15:02:52.172843, 2022-02-01 02:39:28.265445, 2020-09-05 01:42:50.605016	When an instructor last requested to publish the task plan ( tasks_task_plans.publish_last_requested_at )
first_published_at	VARCHAR	datetime	98.1%	28,019	0.1%	2021-08-26 19:07:06.782938, 2022-01-06 22:46:57.852721, 2020-06-17 01:12:30.329702	First time the plan was successfully published ( tasks_task_plans.first_published_at )
created_at_plan	VARCHAR	datetime	98.1%	28,019	0.1%	2022-03-22 16:11:59.587938, 2020-05-28 04:14:44.986028, 2023-04-21 12:53:12.472326	Plan creation timestamp from tasks_task_plans.created_at
updated_at_plan	VARCHAR	datetime	98.1%	21,887	0.1%	2020-06-24 12:38:37.784231, 2018-03-27 14:16:59.144611, 2018-09-07 22:28:32.240547	Most recent update to the plan metadata ( tasks_task_plans.updated_at )
withdrawn_at	VARCHAR	datetime	⚠️ 6.3%	1,460	0.1%	2022-09-06 22:58:18.844438, 2022-04-08 21:33:45.875596, 2018-09-13 03:23:18.767757	When was the assignment withdrawn by the instructor
last_published_at	VARCHAR	datetime	98.1%	20,616	0.1%	2022-07-08 21:50:16, 2020-06-26 04:42:38.040295, 2019-05-06 16:49:56.640985	Timestamp for the latest publish action on the task plan ( tasks_task_plans.last_published_at )
updated_by_instructor_at	VARCHAR	datetime	⚠️ 36.9%	12,932	0.1%	2022-02-19 00:13:13.459835, 2021-08-10 18:47:47.197136, 2022-11-30 14:59:24.258577	When was the assignment updated by instructor
created_at_exercise	VARCHAR	datetime	59.4%	3,072,812	18.5%	2021-09-22 16:43:37.548762, 2021-06-28 12:49:04.415223, 2021-09-20 16:41:09.351951	When was the exercise created
updated_at_exercise	VARCHAR	datetime	59.4%	13,924,518	83.7%	2020-10-06 13:42:37.260637, 2018-10-22 15:59:01.459424, 2020-11-04 21:47:31.200636	When was the exercise updated
last_graded_at	VARCHAR	datetime	⚠️ 0.1%	37,905	100.0%	2022-03-11 17:25:49.697624	When the assignment step was last graded

📝 Text (15 columns)

Free-form text columns

Column	Data Type	Variable Type	Completeness	Unique Values	Cardinality	Sample Values	Description
title	VARCHAR	text	100.0%	13,544	0.1%	module 1, 2.6, 2.7 reading, Homework 5	Assignment title
research_identifier	VARCHAR	text	100.0%	54,138	0.2%	r315a4f9d, rbfd1701b, r51bcbae0	Anonymized student ID
title_plan	VARCHAR	text	98.1%	13,511	0.1%	1D Kinematics (2.1 - 2.8) second chance, HW 2, Ch 5 Applications of Newton's Law	Assignment title
description	VARCHAR	text	⚠️ 47.6%	2,680	0.0%	The Immune System, Reading assignments are to be completed prior t..., Complete these questions to check your understa...	Assignment instructions
settings	VARCHAR	text	98.1%	17,037	0.1%	{"page_ids":["76887","76888","76889"]}, {"exercises":[{"id":"500581","points":[1]},{"id..., {"page_ids":["76964","76965","76966","76967","7...	Instructor selections while creating assignment
url	VARCHAR	text	59.0%	54,418	0.3%	https://exercises.openstax.org/exercises/16045@2, https://exercises.openstax.org/exercises/315@5, https://exercises.openstax.org/exercise/12113@7	Exercise URL to retrieve question details from
free_response	VARCHAR	text	⚠️ 41.3%	4,872,271	42.1%	When I push down on a table while I am on a sca..., UAG CAA CAU GAC AUC CUA UUU, 6.22*10^5	Student response to the question
response_validation	VARCHAR	text	⚠️ 39.9%	7,996,818	71.7%	{"attempts": [{"nudge": "Give it another shot",..., {"attempts": [{"nudge": "Take another chance", ..., {"attempts": [{"nudge": "Try again", "valid": t...	Free response input quality evaluation
answer_ids	VARCHAR	text	59.4%	159,661	1.0%	{300880,300881,300882,300883}, {224567,224568,224566,224565}, {299536,299537,299538,299539}	Multiple-choice response options index
grader_comments	VARCHAR	text	⚠️ 0.1%	6,078	16.0%	No samples available	Grader feedback to free-response grades
published_comments	VARCHAR	text	⚠️ 0.1%	4,575	17.1%	No samples available	Grader feedback shared with students
page_url	VARCHAR	text	96.6%	8,421	0.0%	https://archive.cnx.org/contents/8d50a0af-948b-..., https://archive.cnx.org/contents/405335a3-7cff-..., https://openstax.org/apps/archive/20210713.2056...	Link to textbook content, not valid
tags_array	VARCHAR[]	text	59.4%	72,124	0.4%	blooms:2, dok:2, k12phys-ch01-s02-lo03	Array of all metadata tags associated with the exercise

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📈 Summary Statistics

Dataset Overview

Attribute	Value
Total Rows	27,996,816
Total Columns	95
Total Cells	2,939,665,680
Profiling Time	90.41 seconds
Profiling Speed	32,515,040 cells/second

Column Types Distribution

Data Type	Count	Percentage
VARCHAR	64	61.0%
INTEGER	25	23.8%
DOUBLE	8	7.6%
BOOLEAN	6	5.7%
TIMESTAMP WITH TIME ZONE	1	1.0%
VARCHAR[]	1	1.0%

Variable Types Distribution

Variable Type	Count	Percentage
Identifier	28	26.7%
Categorical	24	22.9%
Datetime	22	21.0%
Text	15	14.3%
Boolean	6	5.7%
Continuous	5	4.8%
Discrete	4	3.8%
Empty	1	1.0%

Data Completeness

Completeness Level	Column Count	Status
Complete (0% nulls)	39	✅
Mostly Complete (1-10% nulls)	33	✅
Partial (11-50% nulls)	16	⚠️
Sparse (51-90% nulls)	6	❌
Mostly Empty (>90% nulls)	11	❌

Overall Data Completeness: 80.3%

Cardinality Analysis

Cardinality indicates the uniqueness of values in each column.

Cardinality Level	Column Count	Description
Very High (>95% unique)	5	Likely identifiers
High (50-95% unique)	4	High variability
Medium (10-50% unique)	4	Moderate variability
Low (<10% unique)	91	Categorical/Boolean

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📖 Glossary

Term	Definition
Cardinality	The number of unique values in a column relative to total non-null values. High cardinality means many unique values.
Completeness	Percentage of non-null values in a column. Higher is better.
Data Type	The technical storage type (e.g., INTEGER, VARCHAR, BOOLEAN).
Identifier	A column containing unique values that identify records (e.g., ID, UUID).
Missing Values	Null, empty, or placeholder values (NA, null, empty string).
Null Percentage	The proportion of null/missing values in a column.
Sample Values	Example values from the column to illustrate its contents.
Variable Type	The semantic meaning of the column (categorical, continuous, etc.).

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