DATA ANALYTICS AND VISUALIZATION USING TABLEAU: BOX PLOT

 The Data Analyst was requested by the Dean of a private university to analyze the students’ performance in “On-the-Job” training considering the evaluation of his/her company supervisor, his/her OJT teacher, and Written Assessment scores. The Dean said 5 out of 20 attended the OJT preparation summer course.

The goal is to analyze if the OJT preparation training helps in increasing students’ performance.

The objective is to create this Box-Plot:

The data is as follow:

Student Performance in OJT evaluation

OJT preparation course	Supervisor Evaluation	OJT Teacher Evaluation	Written Assessment scores
None	73	73	75
attended	70	91	89
None	91	96	94
None	55	57	55
None	77	79	76
None	72	84	79
attended	89	96	94
None	50	54	59
attended	65	65	68
None	48	61	51
None	59	55	53
None	41	53	44
None	66	82	74
attended	79	73	71
None	51	54	59
None	70	76	79
None	88	89	86
None	20	33	29
attended	47	43	47
None	55	59	62

 Step 1.  Drag the “OJT Preparation Course” and “Type of Assessment” into Columns and “Grades” into Columns.

Step 2. Since the data is aggregated, click on “Analysis” and unselect “Unaggregated Measures”. Select

     Box Plot chart type in the “Show Me” toolbar.

Step 3. Drag “Type of Assessment” into color in the Marks and select “Entire View” on the top toolbar.

Step 4. Final Box Plot is shown below.

Analysis:

The Box Plot shows students who took the OJT Preparation Training scored higher than those who did not. They get higher grades in the Supervisor evaluation and for Written Assessment those who attended the OJT preparation training were more clustered above the median.

In conclusion, students who took the OJT Preparation Training performed better in all types of assessment. 

Arnel Lopez Cadeliña, MBA, RREA, CFA (Investment Foundation)