Classify adopters accordingly to Time of Adoption and Threshold levels.

Source: R/stats.R

Adopters are classified as in Valente (1995). In general, this is done depending on the distance in terms of standard deviations from the mean of Time of Adoption and Threshold.

classify_adopters(...)

classify(...)

# S3 method for class 'diffnet'
classify_adopters(graph, include_censored = FALSE, ...)

# Default S3 method
classify_adopters(
  graph,
  toa,
  t0 = NULL,
  t1 = NULL,
  expo = NULL,
  include_censored = FALSE,
  ...
)

# S3 method for class 'diffnet_adopters'
ftable(x, as.pcent = TRUE, digits = 2, ...)

# S3 method for class 'diffnet_adopters'
as.data.frame(x, row.names = NULL, optional = FALSE, ...)

# S3 method for class 'diffnet_adopters'
plot(x, y = NULL, ftable.args = list(), table.args = list(), ...)

Arguments

...

Further arguments passed to the method.

graph

A dynamic graph.

include_censored

Logical scalar, passed to threshold.

toa

Integer vector of length \(n\) with times of adoption.

t0

Integer scalar passed to threshold and toa_mat.

t1

Integer scalar passed to toa_mat.

expo

Numeric matrix of size \(n\times T\) with network exposures.

x

A diffnet_adopters class object.

as.pcent

Logical scalar. When TRUE returns a table with percentages instead.

digits

Integer scalar. Passed to round.

row.names

Passed to as.data.frame.

optional

Passed to as.data.frame.

y

Ignored.

ftable.args

List of arguments passed to ftable.

table.args

List of arguments passed to table.

Value

A list of class diffnet_adopters with the following elements:

toa

A factor vector of length \(n\) with 4 levels: "Early Adopters", "Early Majority", "Late Majority", and "Laggards"

thr

A factor vector of length \(n\) with 4 levels: "Very Low Thresh.", "Low Thresh.", "High Thresh.", and "Very High Thresh."

Details

Classifies (only) adopters according to time of adoption and threshold as described in Valente (1995). In particular, the categories are defined as follow:

For Time of Adoption, with toa as the vector of times of adoption:

  • Early Adopters: toa[i] <= mean(toa) - sd(toa),

  • Early Majority: mean(toa) - sd(toa) < toa[i] <= mean(toa) ,

  • Late Majority: mean(toa) < toa[i] <= mean(toa) + sd(toa) , and

  • Laggards: mean(toa) + sd(toa) < toa[i] .

For Threshold levels, with thr as the vector of threshold levels:

  • Very Low Thresh.: thr[i] <= mean(thr) - sd(thr),

  • Low Thresh.: mean(thr) - sd(thr) < thr[i] <= mean(thr) ,

  • High Thresh.: mean(thr) < thr[i] <= mean(thr) + sd(thr) , and

  • Very High. Thresh.: mean(thr) + sd(thr) < thr[i] .

By default threshold levels are not computed for left censored data. These will have a NA value in the thr vector.

The plot method, plot.diffnet_adopters, is a wrapper for the plot.table method. This generates a mosaicplot plot.

References

Valente, T. W. (1995). "Network models of the diffusion of innovations" (2nd ed.). Cresskill N.J.: Hampton Press.

Author

George G. Vega Yon

Examples

# Classifying brfarmers -----------------------------------------------------

x <- brfarmersDiffNet
diffnet.toa(x)[x$toa==max(x$toa, na.rm = TRUE)] <- NA
out <- classify_adopters(x)

# This is one way
round(
with(out, ftable(toa, thr, dnn=c("Time of Adoption", "Threshold")))/
  nnodes(x[!is.na(x$toa)])*100, digits=2)
#>                  Threshold Non-Adopters Very Low Thresh. Low Thresh. High Thresh. Very High Thresh.
#> Time of Adoption                                                                                   
#> Non-Adopters                      28.15             0.00        0.00         0.00              0.00
#> Early Adopters                     0.00             7.96        3.70         0.74              1.11
#> Early Majority                     0.00             8.89       10.56         4.63              4.63
#> Late Majority                      0.00             6.30       10.19         8.70             16.30
#> Laggards                           0.00             1.48        1.11         2.22             11.48

# This is other
ftable(out)
#>                thr Non-Adopters Very Low Thresh. Low Thresh. High Thresh. Very High Thresh.
#> toa                                                                                        
#> Non-Adopters              21.97             0.00        0.00         0.00              0.00
#> Early Adopters             0.00             6.21        2.89         0.58              0.87
#> Early Majority             0.00             6.94        8.24         3.61              3.61
#> Late Majority              0.00             4.91        7.95         6.79             12.72
#> Laggards                   0.00             1.16        0.87         1.73              8.96

# Can be coerced into a data.frame, e.g. ------------------------------------
 str(classify(brfarmersDiffNet))
#> List of 3
#>  $ toa    : Factor w/ 5 levels "Non-Adopters",..: 4 5 4 3 3 4 4 3 5 4 ...
#>  $ thr    : Factor w/ 5 levels "Non-Adopters",..: 4 4 4 3 3 4 4 3 4 4 ...
#>  $ cutoffs:List of 2
#>   ..$ toa: num [1:3] 1955 1960 1965
#>   ..$ thr: num [1:3] 0.206 0.614 1.021
#>  - attr(*, "class")= chr "diffnet_adopters"
 ans <- cbind(
 as.data.frame(classify(brfarmersDiffNet)), brfarmersDiffNet$toa
 )
 head(ans)
#>                 toa          thr brfarmersDiffNet$toa
#> 1001  Late Majority High Thresh.                 1961
#> 1002       Laggards High Thresh.                 1965
#> 1004  Late Majority High Thresh.                 1963
#> 1005 Early Majority  Low Thresh.                 1957
#> 1007 Early Majority  Low Thresh.                 1959
#> 1009  Late Majority High Thresh.                 1960

# Creating a mosaic plot with the medical innovations -----------------------
x <- classify(medInnovationsDiffNet)
plot(x)