Appendix A - Wyoming Severe Discrepancy Formula

Current through April 27, 2019

Consistent with 34 C.F.R. § 300.307, a school district or public agency is not required to use the Wyoming Severe Discrepancy Formula in order to find a child eligible for special services under the category of Specific Learning Disability (SLD). In the event a school district or public agency elects to establish a child's eligibility under the category of SLD through use of a severe discrepancy model, the school district or public agency must use the Wyoming Severe Discrepancy Formula and document compliance on the eligibility report.

The assessment of intellectual ability and academic functioning level must include individually administered norm-reference tests that are reliable and valid, and administered by an individual specifically trained to administer and interpret the instruments. Criterion-referenced tests, informal measures, work samples, classroom observations, and the child's educational history may be used as needed to corroborate norm-referenced test scores.

A child whose disability is a Specific Learning Disability must demonstrate a severe discrepancy between current achievement level and expected achievement level of 22 points upon initial evaluation. Expected achievement level (obtained from Table A) is based on the correlation between tests of the child's composite intellectual standard score compared to the child's composite achievement score in one (1) or more core achievement areas.

Instructions:

In all cases, intellectual and achievement standard scores should be based on age norms rather than grade norms and, when available, on cluster scores rather than on subtest scores. Using the most current editions and norms of any chosen standardized tests is preferable to using older editions with outdated norms.

The table on the following page entitled Correlation Coefficient Between Ability and Achievement Test Scores should be used to determine the child's expected achievement level. This table takes into account the correlation between the intellectual and achievement measures being used as well as regression toward the mean. To use this table, the steps outlined below must be followed:

Step 1: Determine the correlation between the intellectual and achievement measures being used, if available. If the correlation between intellectual and achievement measures is not known, .65 may be used as an adequate median correlation between such measures.

Step 2: Locate the child's intellectual standard score in the side columns of Table A, entitled Correlation Coefficient Between Ability and Achievement Test Scores.

step 3: Follow the row determined In Step 2 to the column with the correlation value closest to the correlation between the] chosen measures of intellectual functioning and achievement or to a correlation of ,65 if a specific correlation coefficient Is not known.

Ability Score	Table A: Correlation Coefficient Between Ability and Achievement Test Scores											Ability Score
	0.4	0.45	0.5	0.55	0.6	0.65	0.7	0.75	0.8	0,85	0.9
	Expected Achievement Score with Correction for Regression Toward the Mean
130	112	114	115	117	118	120	121	123	124	126	127	130
129	112	113	115	116	117	119	120	122	123	125	126	129
128	111	113	114	115	117	118	120	121	122	124	125	128
127	111	112	114	115	116	118	119	120	122	123	124	127
126	110	112	113	114	116	117	118	120	121	122	123	126
125	110	111	113	114	115	116	118	119	120	121	122	125
124	110	111	112	113	114	116	117	118	119	120	122	124
123	109	110	112	113	114	115	116	117	118	120	121	123
122	109	110	111	112	113	114	115	117	118	119	120	122
121	108	109	111	112	113	114	115	116	117	118	119	121
120	108	109	110	111	112	113	114	115	116	117	118	120
119	108	109	110	110	111	112	113	114	114	116	117	119
118	107	108	109	110	111	112	113	114	114	115	116	118
117	107	108	109	109	110	111	112	113	114	114	115	117
116	106	107	108	109	110	110	111	112	113	114	114	116
115	106	107	108	108	109	110	111	111	112	113	114	115
114	106	106	107	108	108	109	110	111	111	112	113	114
113	105	106	107	107	108	108	109	110	110	111	112	113
112	105	105	106	107	107	108	108	109	110	110	111	112
111	104	105	106	106	107	107	108	108	109	109	110	111
110	104	105	105	106	106	106	107	108	108	109	109	110
109	104	104	105	105	105	106	106	107	107	108	108	109
108	103	104	104	104	105	105	106	106	106	107	107	108
107	103	103	104	104	105	105	105	105	106	106	106	107
106	102	103	103	103	104	104	104	105	105	105	105	106
105	102	102	103	103	103	103	104	104	104	104	104	105
104	102	102	102	102	102	103	103	103	103	103	104	104
103	101	101	102	102	102	102	10,2	102	102	103	103	103
102	101	101	101	101	101	101	101	101	102	102	102	102
101	100	100	101	101	101	101	101	101	101	101	101	101
100	100	100	100	100	100	100	100	100	100	100	100	100
99	100	100	100	99	99	99	99	99	99	99	99	99
98	99	99	99	99	99	99	99	99	98	98	98	98
97	99	99	99	98	98	98	98	98	98	97	97	97
96	98	98	98	98	98	97	97	97	97	97	96	96
95	98	98	98	97	97	97	97	96	96	96	96	95
94	98	97	97	97	96	96	96	96	95	95	95	94
93	97	97	97	96	96	95	95	95	94	94	94	93
92	97	96	96	96	95	95	94	94	94	93	93	92
91	96	96	96	95	95	94	94	93	93	92	92	91
90	96	96	95	95	94	94	93	93	92	92	91	90
89	96	95	95	94	93	93	92	92	91	91	90	89
88	95	95	94	93	93	92	92	91	90	90	89	88
87	95	94	94	93	92	92	91	90,	90	89	88	87
86	94	94	93	92	92	91	90	90	89	88	87	86
85	94	93	93	92	91	90	90	89	88	87	86	85
84	94	93	92	91	90	90	89	88	87	86	86	84
83	93	92	92	91	90	89	88	87	86	86	85	83
82	93	92	91	90	89	88	87	87	86	85	84	82
81	92	91	91	90	89	88	87	86	85	84	83	81
80	92	91	90	89	88	87	86	85	84	83	82	80
79	92	91	90	88	87	86	85	84	83	82	81	79
78	91	90	89	88	87	86	85	84	82	81	80	78
77	91	90	89	87	86	85	84	83	82	80	79	77
76	90	89	88	87	86	84	83	82	81	80	78	76
75	90	89	88	86	85	84	83	81	80	79	78	75
74	90	88	87	86	84	83	82	81	79	78	77	74
73	89	88	87	85	84	82	81	80	78	11	76	73
72	89	87	86	85	83	82	80	79	78	76	75	72
71	88	87	86	84	83	81	80	78	77	75	74	71
70	88	86	85	84	82	80	79	78	76	74	73	70