Does 'When' really feel more certain than 'If'? Two failures to replicate Ballard and Lewandowsky (2015)

Area of Science:

• Psychology
• Environmental Science
• Communication Studies

Background:

• Previous research suggested presentation format of uncertain information influences public certainty and concern regarding climate change.
• Ballard & Lewandowsky (2015) found that presenting a certain outcome with an uncertain timeframe increased certainty and concern compared to a range of outcomes by a certain timeframe.

Purpose of the Study:

• To conceptually replicate the findings of Ballard & Lewandowsky (2015) regarding the impact of information presentation on public perception of climate change.
• To investigate whether focusing on a certain outcome with an uncertain timeframe increases certainty and concern more than a range of outcomes with a certain timeframe.

Main Methods:

• Two independent studies were conducted to test the original findings.
• Participants were presented with different formats of projected climate change information.

Main Results:

• Both studies found a null effect, failing to replicate the original findings.
• There was no significant difference in certainty or concern based on the presentation format of the projection statements.

Conclusions:

• The findings suggest that the presentation format of uncertain information, as used in the original studies, may not significantly impact public certainty and concern.
• Researchers recommend treating these projection statements as equivalent.
• There is a need to explore alternative methods for effectively communicating uncertain information about future public health and environmental events.