Reliability

Introduction

Reliability is the overall consistency of a measure. Reliability is usually evaluated using Cronbach's α (alpha), a metric that reflects the consistency of results across items within a scale. In published assessments, a Cronbach's α of .7 is considered minimally acceptable, .8 is considered good, and .9 is considered excellent. Ideally, all scales on an assessment should have a Cronbach's α of .8 or higher. In real life, few assessments meet that goal.

All of CareerExplorer's scales have Cronbach's α above .8. The average reliability is .88, and the minimum is .82. This level of reliability suggests that CareerExplorer's assessment is suitable for use in both personal and high-stakes testing.

Full Results

Scale	Sample	# of Items	α
Holland Codes 5-point scale from 1=Hate it to 5=Love it
Artistic	16 635	8	0.85
Conventional	16 770	6	0.87
Enterprising	14 418	10	0.84
Investigative	16 665	6	0.87
Realistic	16 664	6	0.86
Social	16 651	8	0.84
Work Styles / Personality 5-point scale from 1=Strongly disagree to 5=Strongly agree
Achievement/Effort	14 341	8	0.86
Adaptability/Flexibility	12 455	10	0.85
Analytical thinking	12 460	10	0.91
Attention to detail	14 307	8	0.88
Concern for others	12 443	10	0.87
Cooperation	12 495	12	0.86
Dependability	14 343	9	0.89
Impression management	2441	14	0.81
Independence	12 548	12	0.82
Initiative	11 844	10	0.85
Innovation	14 456	6	0.92
Integrity	14 324	6	0.83
Leadership	14 475	6	0.92
Persistence	14 324	10	0.88
Self control	14 364	9	0.89
Social orientation	14 307	7	0.88
Basic Interests 5-point scale from 1=Hate it to 5=Love it
Adventure	13 355	7	0.86
Athletics	13 347	5	0.87
Beauty & style	11 579	6	0.88
Business	13 393	5	0.90
Counseling and helping	11 661	6	0.88
Creative arts	13 353	5	0.90
Creative writing & journalism	11 643	5	0.90
Culinary arts	13 340	5	0.87
Engineering	13 396	5	0.87
Family activity	11 595	8	0.90
Finance	13 377	5	0.90
Green industry	11 625	6	0.92
Healthcare service	13 342	6	0.87
Human relations management	11 610	6	0.87
Information technology	13 431	5	0.90
Law	13 345	5	0.90
Life science	11 930	5	0.89
Management	13 339	6	0.86
Manual labor	13 343	6	0.84
Mathematics	11 654	5	0.93
Military	11 590	4	0.93
Nature and agriculture	10 230	11	0.89
Office clerical work	10 245	8	0.88
Performing arts	11 607	5	0.87
Personal service	10 243	11	0.88
Physical science	13 524	5	0.88
Politics	11 634	5	0.92
Professional advising	11 626	5	0.88
Protective services	11 621	8	0.89
Religion & spirituality	11 619	5	0.89
Sales	11 604	5	0.89
Skilled trades	13 367	5	0.88
Social sciences	13 404	5	0.86
Teaching	13 481	5	0.88
Technical writing	11 640	5	0.88
Working with animals	11 641	5	0.90

Cronbach's α (alpha) is a measure of reliability. Higher values are better. Ideally, all scales on an assessment should have an α of .8 or higher. In real life, few assessments meet that goal.