Table 1

Basic Data Usage Index indicators for primary biodiversity data published through the GBIF network

Formula

Indicator

Description

1

s(u)

Searched records

Number of records searched/viewed (by IP address) in unit

2

d(u)

Download frequency

Number of downloaded records from unit

3

r(u)

Record number

Number of records in (period; dataset(s); geographical and/or species unit)

4

S(u)

Search events

Number of different searches (by IP address) in unit

5

D(u)

Download events

Number of different downloads from unit

6

N(u)

Dataset number

Number of datasets in (period, geographical and/or species unit)

7

s(u)/S(u)

Search density

Average number of searched records per search event

8

d(u)/D(u)

Download density

Average download frequency per download event

9

d(u)/r(u)

Usage impact

Download frequency per stored record per unit

10

s(u)/r(u)

Interest impact

Searched records per stored record per unit

11

d(u)/s(u)

Usage ratio

Ratio of download frequency to searched records in unit

12

D(u)/S(u)

Usage balance

Ratio of download events to search events for unit (in %)

13

U(u)/r(u)

Usage score

Ratio of unique downloaded records (U) to record number (in %)

14

I(u)/r(u)

Interest score

Ratio of unique searched records (I) to record number (in %)

Ingwersen and Chavan BMC Bioinformatics 2011 12(Suppl 15):S3   doi:10.1186/1471-2105-12-S15-S3