Do Markers of Verbal Confidence Correlate with Effect Size in Studies of Pollution Bioindicators?
Abstract
Bioindicators are organisms whose status or physiological condition are used to assess the effects of stressors such as pollution on ecosystems. Commonly used bioindicators include population-level responses in environmentally sensitive insects (e.g., Ephemeroptera, Plectoptera, and Trichoptera) and fishes (e.g., slimy sculpins, fish larvae), or specific individual-level responses such as EROD enzyme induction or fecundity. Parasites were first proposed as biological indicators of pollution in the 1990s. Parasites are ubiquitous components of aquatic ecosystems, and are known to respond to pollution: while some parasites increase in abundance in polluted areas, most exhibit decreased abundance, and polluted environments typically have species-poor parasite communities. Since the 1990s, more than 500 studies have assessed the use of parasites as bioindicators of pollution, and meta-analyses have confirmed that the associated effect sizes can be significant. Nevertheless, parasites are only rarely included in government-mandated pollution monitoring programs, suggesting that there is a perceptual disconnect between the actual vs. perceived validity of using parasites as bioindicators. To further examine this disconnect, we conducted a meta-analysis of studies of parasite responses to pollution. We calculated mean effect sizes (Cohen’s d) for each study; we then used used text analysis software (LIWC2015) to quantify verbal markers of author confidence (i.e., affect words indicating positive or negative emotion, and author certainty vs. tentativeness). We then calculated the extent to which the effect sizes were correlated with the authors’ language. We also assessed whether authors’ perception of the usefulness of parasites as bioindicators has changed over time.
Faculty Sponsors
Dr. Christopher Blanar
Project Type
Event
Location
Alvin Shermany Library
Start Date
4-5-2019 1:00 PM
End Date
4-5-2019 5:00 PM
Do Markers of Verbal Confidence Correlate with Effect Size in Studies of Pollution Bioindicators?
Alvin Shermany Library
Bioindicators are organisms whose status or physiological condition are used to assess the effects of stressors such as pollution on ecosystems. Commonly used bioindicators include population-level responses in environmentally sensitive insects (e.g., Ephemeroptera, Plectoptera, and Trichoptera) and fishes (e.g., slimy sculpins, fish larvae), or specific individual-level responses such as EROD enzyme induction or fecundity. Parasites were first proposed as biological indicators of pollution in the 1990s. Parasites are ubiquitous components of aquatic ecosystems, and are known to respond to pollution: while some parasites increase in abundance in polluted areas, most exhibit decreased abundance, and polluted environments typically have species-poor parasite communities. Since the 1990s, more than 500 studies have assessed the use of parasites as bioindicators of pollution, and meta-analyses have confirmed that the associated effect sizes can be significant. Nevertheless, parasites are only rarely included in government-mandated pollution monitoring programs, suggesting that there is a perceptual disconnect between the actual vs. perceived validity of using parasites as bioindicators. To further examine this disconnect, we conducted a meta-analysis of studies of parasite responses to pollution. We calculated mean effect sizes (Cohen’s d) for each study; we then used used text analysis software (LIWC2015) to quantify verbal markers of author confidence (i.e., affect words indicating positive or negative emotion, and author certainty vs. tentativeness). We then calculated the extent to which the effect sizes were correlated with the authors’ language. We also assessed whether authors’ perception of the usefulness of parasites as bioindicators has changed over time.
