Calculate the CD (disruption) index

Computes the CD index (Funk & Owen-Smith, 2017) for each work in the corpus. The CD index measures how disruptive a work is by comparing the citation patterns of papers that cite the focal work versus those that cite its references.

Usage

sm_metric_disruption(corpus, call = rlang::caller_env())

Arguments

corpus

An sm_corpus object with a populated references table.

call

Caller environment for error reporting.

Value

A tibble with columns work_id and cd_index. The CD index ranges from -1 (consolidating) to +1 (disruptive). Works without sufficient citation data receive NA.

Details

The CD index is defined as:

$$CD = \frac{n_i - n_j}{n_i + n_j + n_k}$$

Where for a focal work f:

n_i

Number of works that cite f but do NOT cite any of f's references (disruptive citations).

n_j

Number of works that cite BOTH f and at least one of f's references (consolidating citations).

n_k

Number of works that cite at least one of f's references but do NOT cite f (ignored-but-referencing citations).

A CD index near +1 indicates the focal work is highly disruptive: its citers tend to ignore its references. A CD index near -1 indicates the focal work consolidates existing ideas.

References

Funk, R. J., & Owen-Smith, J. (2017). A Dynamic Network Measure of Technological Change. Management Science, 63(3), 791–817. doi:10.1287/mnsc.2015.2366

See also

Other metrics: sm_metric_collab_index(), sm_metric_fnci(), sm_metric_g_index(), sm_metric_h_index(), sm_metric_m_index(), sm_metric_novelty(), sm_metric_rcr(), sm_self_citation(), sm_summary_authors(), sm_summary_period(), sm_summary_sources(), sm_summary_works()

Examples

corpus <- sm_example_corpus()
cd <- sm_metric_disruption(corpus)
head(cd)
#> # A tibble: 6 × 2
#>   work_id    cd_index
#>   <chr>         <dbl>
#> 1 W000000001   0     
#> 2 W000000002   0.0101
#> 3 W000000003  -0.0642
#> 4 W000000004   0.167 
#> 5 W000000005   0.0303
#> 6 W000000006   0.188