What are Altmetrics?
Altmetrics can be defined either as alternative metrics or article metrics. Both are appropriate definitions: altmetrics offer an alternative, or non-traditional method of evaluating research, and can be based more specifically on the article and how it is received, rather than the reputation or impact factor of the journal it is published in.
According to Altmetric (www.altmetric.com), a company specializing in article data, ‘altmetrics can showcase the attention and influence in research, which may not be measured accurately using traditional methods such as the impact factor or h-index."
Impact factors are based on the average number of times that articles of a certain journal are cited, and therefore indicate how reputable the journal is in terms of its citation impact. It can therefore be assumed that an article published in the same journal must also be reputable in the same way. This means that the article is evaluated only in relation to the journal in which it is published, rather than on its own intrinsic worth. Similarly, the h-index measures the output of individuals, rather than evaluating each research paper produced by an individual.
Altmetric argues, therefore, that altmetrics can offer more reliable data on the individual article. Such data can be obtained through various means, as altmetrics do not apply to just one indexing method, but can apply to any method of evaluating an article which does not involve traditional means such as those mentioned above.
For example, the online dissemination of an article can be tracked in order to identify how many people are exposed to the paper and how many engage with it. However, the results could be falsified by someone repeatedly downloading it to enhance the statistics. Countering this, how many times an article is cited, by whom, and in which online contexts or document types can also be measured. This means the impact of the individual article can be measured in terms of how many people it reaches and how influential it is.
While such data help gain a more meaningful picture of the impact of the article in different online social, scientific or institutional spheres, there is no indication of the value of the article within the wider scientific community. This is because companies such Altmetric are able to track the article online but not offline; more traditional indices may still be needed to determine the reliability of the article by measuring the reputation of the writer him- or herself, or the impact factor of the journal it was originally published in.
As such, altmetrics are often used complement traditional metrics in order to gain further insight into the impact of an article.