The Real Deal Or
Deceptive Advertising? September 1, 2017 By Steven Kammerer, regional director, Southeast Region

Evaluate research cited in support of a product or turfgrass to ensure the data is scientifically valid and applicable to your specific situation.

Data, images and research summaries often are used to sell a product or message. Based on how information is presented, however, very different conclusions may be drawn. For this reason it is important to evaluate marketing materials with a critical eye.

Pictures: Are the images representative of how a product will perform at your golf course? Images of side-by-side comparisons can be eye catching, but they may not accurately represent product performance because environmental conditions, soils and pest pressures are seldom identical from one site to another. Be aware that side-by-side images may not always be taken from controlled research plots at the same location, so some of the variability in appearance could be attributed to factors other than product or variety performance.

Charts: Charts and graphs are common methods of presenting data. They provide a visual comparison that is easier to interpret than a table full of numbers. However, remember to carefully check the scale and range of the chart axes. Manipulating axes can make differences between treatments or products appear much larger than actual.

Statistics: Statistics may not be as exciting as images, videos or colorful bar charts, but statistics are critically important to determine the validity of marketing materials. Statistics can tell you whether marketing materials are based on actual differences in product performance or whether claims are based on limited information. Whenever presented with statistics, take care to look for information about the data being summarized and the methods used in the analysis. While statistics can provide valuable information about differences in product performance, they are only as reliable as the data they summarize. If no statistics are presented, or if the source of data is unclear, reevaluate the claims being made and ask for clarification.

Who generated the data and where?  Some researchers, universities and company research facilities have more experience working with golf course turfgrass than others. It is important to consider the source of any research presented in support of a product or practice.

How is the data interpreted? Be cautious about how results are interpreted because you may not have full information about the untreated condition. If there were only five crabgrass weeds in a large plot and four were killed by an herbicide treatment, the herbicide could be said to have 80-percent control. However, extrapolating this result as an indication of how the herbicide performs under greater weed pressure is misleading because the result was derived from an environment with low crabgrass pressure.

When was the test assessed? Trials often require frequent applications or repeated activities during which there are often periods of low and high environmental stress or pest levels. It is important to evaluate the timing of a study to understand whether a product is likely to produce consistent results across a broad range of conditions.

When researching a product or turfgrass variety, it is absolutely essential to get some reassurance that what is being tested does what it is supposed to do. However, the materials presented in support of a product should always be viewed with a critical eye. When in doubt, ask to see the raw data from supporting studies or contact the researcher that performed the trial to learn more about their conclusions. You should also contact other superintendents and ask about their results and conclusions. USGA Agronomists are another excellent resource because they see hundreds of golf courses each year and are familiar with current scientific research.


Southeast Region Agronomists:

Chris Hartwiger, director, USGA Course Consulting Service –

Steve Kammerer, regional director –

Patrick M. O’Brien, agronomist –

Todd Lowe, agronomist –

Information on the USGA’s Course Consulting Service

Contact the Green Section Staff

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