CHICAGO — Marketers can now have insight into which brands are most recommended — as well as why and how — across a variety of consumer categories thanks to the launch of the newly created Recommendation Index (R.I.), a joint effort between Zocalo Group and M/A/R/C Research, the partners announced.

The index provides an overall ranking of both positively and negatively recommended brands and it also creates a score that marketers can use to compare against other brands in the same category. Restaurants that serve moderately priced food in a casual atmosphere — the casual dining restaurant (C.D.R.) segment — will be the initial focus of what will be quarterly reports examining a variety of industries.

Topping the R.I. of the 10 most-recommended brands are California Pizza Kitchen, Texas Roadhouse and Outback Steakhouse, followed by Applebee's and the Cheesecake Factory. Except for buffet-style restaurants, C.D.R.s typically provide table service and comprise a market segment between fast food and fine-dining establishments.

Different from previous metrics that only ask "Would you recommend this brand?" the R.I. evolves the measurement to determine why, where and how often people recommend individual brands, as well as how each brand compares to the overall category, according to its creators.

"The recommendation of a friend, family member or expert is the number-one reason consumers buy in almost every category," said Paul M. Rand, president and chief executive officer of Zocalo Group. "Marketers who understand where and how their category is talked about and recommended — and how their brand stacks up — gain clear competitive advantage."

Top words or characteristics consumers use when making a positive or negative recommendation for a casual dining restaurant are identified in the study. Triggers such as "fast," "variety," and "friendly" are among top indicators.

The R.I. looks at how consumers talk and their actions, "We wanted to move from the hypothetical to the actual. The potential implications for brands are significant," said Merrill Dubrow, president and chief executive officer of M/A/R/C Research.

The R.I. represents the proportion of positive to negative recommendations and is calculated based on the brands most-often talked about positively and negatively in the C.D.R. category. It is a single score that provides a brand with a method for benchmarking how it is being recommended in relation to specific competitors and within the overall industry.

The average R.I. for C.D.R.s of 3.01 is the average Index value of the most recommended brands in the category. The average provides brands with a means for gauging the level of recommendation against the overall industry.

"Once marketers truly understand why and how brands are recommended in their category, they can adjust their messaging, communications — and even their operations — to ensure that they become and stay the most recommended," Mr. Rand said.