Coming off of a weak back-to-school shopping period, a research firm expects holiday sales growth will be slower this year during the crucial holiday season. Shoppers are also expected to visit fewer stores as they research purchases online.

Retail revenue in November and December should rise 2.4 percent during the biggest shopping period of the year, Chicago-based research firm ShopperTrak said Tuesday. That compares with a 3 percent increase in 2012 from 2011.

"Although the economy continues to recover slowly, consumers remain cautious about spending and are not ready to splurge," said ShopperTrak founder Bill Martin.

While the job picture has been improving in the U.S. and the turnaround in the housing market is gaining traction, the improvements have not been enough to sustain higher levels of spending for most Americans. Most continue to juggle tepid wage gains with a higher cost of living.

In August, revenue at stores opened at least a year — a measure of a retailer's health— rose 3.6 percent, according to a tally of 10 retailers by the International Council of Shopping Centers. That's up a tad from July's 3.5 percent gain, but below the 6 percent gain in August last year. The cautious spending last month capped a weak back-to-school selling season for retailers and raised questions about whether Americans would spend in November and December, a time retailers can make up to 40 percent of their revenue for the year.

ShopperTrak expects traffic will fall 1. 4 percent during November and December, compared with a 2.5 percent increase in 2012. That's partly due to people researching purchases more diligently before they go out shopping, Martin says.

"They're still purchasing the same amount and product they intended to, they're just not roaming from store to store looking for it," he said.

In addition, there's a shorter shopping window between Black Friday — the day after Thanksgiving, which is usually the biggest shopping day of the year — and Christmas. Last year there were 32 days during the period and this year there are 25.

Weekends are the busiest shopping period within that time frame. There are four weekends this year compared with five last year. Because of that, Martin expects stores to bring out their promotions and services like layaway early — Toys R Us and Wal-Mart Stores Inc. have both already announced their layaway plans. Layaway plans let consumers pay over time for holiday gifts.

"Retailers must have their holiday marketing and operations ready to go when November begins, as consumers will be ready to take advantage of those deals," said Martin.

The retail industry is still waiting for a widely watched holiday forecast from the National Retail Federation, the nation's largest retail trade group, which will be issuing its report early October. But the prediction from ShopperTrak, which counts foot traffic at 60,000 stores and blends it with government figures and its own proprietary sales numbers from stores, offers one of the first insights into how shoppers might spend during the season.