3.1 Textual Method

The TEXTUAL METHOD is used when ungoruped data is presented in a paragraph form. The paragraph or text presents (usually through enumeration) the important characteristics of the data. It also gives emphasis to significant figures (or values) and important features of the data such as trends, irregularities and extreme values, if any.

Example:
Listed below are the grades in Statistics of 50 students:

87	85	90	74	82	93	68	72	88	95
91	94	88	86	71	100	76	79	83	81
74	90	84	70	69	77	94	83	71	65
98	75	77	84	82	99	90	86	87	70
92	69	79	89	96	84	86	92	79	84

Here are the Statistics grades of 25 students, arranged from lowest to highest:

65	68	69	69	70	70	71	71	72	74
74	75	76	77	77	79	79	79	81	82
82	83	83	84	84	84	84	85	86	86
86	87	87	88	88	89	90	90	90	91
92	92	93	94	94	95	96	98	99	100

The highest grade is 100, while the lowest grade is 65. Eleven students failed because their grades are lower than 75. Generally, the class performed well since 39 students passed with grades of 75 or higher.

~ O ~

Stem-and-leaf plot - used to easily sort and arrange large chunks of data; table which sorts data according to a specific pattern; involves separating a number into two parts

Example:
The Statistics grades of a sample of 50 students:

Stem	Leaves
6	5, 8, 9, 9
7	0, 0, 1, 1, 2, 4, 4, 5, 6, 7, 7, 9, 9, 9
8	1, 2, 2, 3, 3, 4, 4, 4, 4, 5, 6, 6, 6, 7, 7, 8, 8, 9
9	0, 0, 0, 1, 2, 2, 3, 4, 4, 5, 6, 8, 9
10	0

Based on the stem-and-leaf plot, the fives lowest grades are 65, 68, 69, 69 and 70. While the five highest scores are: 100, 99, 98, 96 and 94.

This entry was posted on Sunday, January 22nd, 2006 at 5:29 am and is filed under 3: Presentation of Data. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.