1. Using the BLS Template (slide hidden from show; may be relocated or deleted) CORE slides – Presentation Title (slide 2) and Contact Info (slide 4) - are mandatory; these have a blue background regardless of the color of the Content slides Other slides – all called Content slides – are optional and available as layout options  Content slides in this template have a white background Using the layouts  To insert slide: Home tab > use New Slide drop down to select – Note that default layout will be the same as previous slide (relative to current location)  To change current layout: Home tab > use Layout drop down to select  On blank slide, click to add text or click diagram placeholder in center to add chart, table, etc. Footers (e.g. date or page numbers)  Insert tab > Header & Footer button > Slide tab > check/uncheck appropriate boxes Font types and sizes are preset; font type (Tahoma) may not be altered  Font may shrink as text expands but, for readability, use font size 20+ – Avoid using bullets (or numbered list) beyond the 3 rd level – Bullet types and colors have been preformatted and should not be altered if used; however, you may use numbered lists of your choosing (color should remain the same as default bullets) Refer to BLS PowerPoint Presentation Guidelines for detailed instructions & guidelinesBLS PowerPoint Presentation Guidelines Last updated: 8/26/09 1

2. Advances in Designing a Statistical Metadata Standard Dan Gillman US Bureau of Labor Statistics Jay Greenfield Booz |Allen | Hamilton

3. DDI Modernization Data Description Subgroup  Variables  Value Domains Work led to  Reduced metadata redundancy  Richer Semantics Appeal to 4 th and 5 th Normal Forms 3

4. Problem Look at ISO/IEC 11179 4 DATA ELEMENT CONCEPT DATA ELEMENT CONCEPTUAL DOMAIN 0..* VALUE DOMAIN 1 CONCEPTUAL LEVEL REPRESENTATIONAL LEVEL 0..* 1 1

5. Problem Change a Conceptual Domain  Must change every related Value Domain – Must change every related Data Element Other examples exist Dependency Cascade Related to database design  Look at Normal Forms 5

6. Normal Forms Allocation of attributes to tables to  Ease maintenance  Reduce input for updates 3 rd NF  “the key, the whole key, and nothing but the key” For most applications, this is enough 6

7. Normal Forms 4 th NF  No table may contain 2 or more 1:N or N:M relationships  Will illustrate with example 5 th NF  Practical constraints justify separating logically related relationships  Again, illustrate with example 7

8. 4 th NF - Example Conceptual Domain – Sex Categories  Male  Female  Other  Refused  Don’t know 8

9. 4 th NF - Example Substantive categories – subject matter  Male  Female  Other Sentinel categories - processing  Don’t know  Refused 9

10. 4 th NF - Example Codes for substantive categories  Malem01  Femalef12 Codes for sentinel categories  (application)SPSSSAS  Don’t know-998.d  Refused-999.r 10

11. 4 th NF - Example So,  3 substantive encodings  2 sentinel encoding Results in 6 (2x3) possible Value Domains However,  Substantive categories describe data  Sentinel categories describe processing 11

12. 4 th NF - Example Separate  Substantive value domain  Sentinel value domain Possibilities,  Substantive (3) + sentinel (2) = 5  Reduction – additive versus multiplicative 12

13. 5 th NF - Example ISO/IEC 11179  no distinction between – Abstract – Application  data elements But, many things related for both  Value domain  Datatype  Etc. 13

14. 5 th NF - Example For practical purposes  Separate – Conceptual Purely conceptual – Represented Independent of software or application – Instance Software or application dependent  Variables in DDI 14

15. 5 th NF - Example Relate  Conceptual Variable to Conceptual Domain  Represented Variable to Subtv. Value Domain  Instance Variable to Sentl. Value Domain Reduces management requirements 15

16. DDI Model for Variables 16 CONCEPTUAL VARIABLE REPRESENTED VARIABLE INSTANCE VARIABLE 0..N SUBSTANTI VE VALUE DOMAIN 1 0..N SUBSTANTIVE CONCEPTUAL DOMAIN 1 0..N SENTINEL VALUE DOMAIN 1 0..N POPULATION 1 0..N UNIVERSE 1 UNIT TYPE

17. Contact Information Dan Gillman Jay Greenfield gillman.daniel@bls.gov greenfield_jay@bah.com gillman.daniel@bls.gov greenfield_jay@bah.com