Earnings season kicks off next week amid high uncertainty on Wall Street--especially concerning the companies below.

Analysts have spent more than seven months steadily lowering their first-quarter earnings forecasts for the broad market. Earnings for the S&P 500 index are now expected to rise 5% from the first quarter of last year, according to S&P. A year ago, the growth rate was 16%.

What remains to be seen is whether estimates have come down far enough for companies to beat them, and how stocks will respond.

The companies below present a different dilemma for investors. The analysts who forecast their earnings show unusually wide disagreement in their numbers. Estimates, in other words, are all over the place.

High levels of "estimate dispersion", as it's called, are generally a negative sign for investors, but not always. Research by Anna Scherbina at the University of California at Davis and others has shown a link between widely scattered estimates and sub-par future stock returns and earnings growth. Companies that have little good news to share tend to give little guidance, the thinking goes, leaving analysts to guess.

Of course, there are other reasons analysts might disagree on their forecasts. Companies that are in a state of rapid change, or whose profits are affected by volatile commodity prices, can produce wide earnings swings that are difficult to predict.

SanDisk

• Earnings date: April 19
• Consensus estimate: 71 cents
• High estimate: $1.00
• Low estimate: 57 cents

SanDisk (SNDK) on Tuesday lowered its first-quarter guidance for revenues and margins, citing weak demand and pricing for its flash memory. Shares tumbled about 12% since then, and earnings estimates plunged. Sandisk counts thriving electronics makers like Apple (AAPL) as customers, but also struggling ones like Nokia (NOK) and Research in Motion (RIMM) .

Goldman Sachs

• Earnings date: April 17
• Consensus estimate: $3.38
• High estimate: $4.00
• Low estimate: $2.03

First-quarter profits for Goldman Sachs (GS) are expected to more than double from a year ago. And whereas most earnings estimates have been trimmed of late, those for Goldman and other banks have risen on improvements in trading, mortgage banking and loan growth. For Goldman in particular, derivatives profits in Europe have soared from clients seeking to hedge risk, Reuters reported in late March, citing internal Goldman documents. The broader U.S. financial sector has been the stock market's top performer this year, rising 20%.

Newfield Exploration

• Earnings date: April 25
• Consensus estimate: 77 cents
• High estimate: $1.10
• Low estimate: 47 cents

Newfield Exploration (NFX) produces more natural gas than oil, but it's working to reverse that. The reason: U.S. natural gas prices have tumbled to nearly a 10-year low while oil prices remain high. New drilling technologies in the U.S. have unlocked vast supplies of both, but because oil is more easily exported overseas, it continues to fetch high prices. First-quarter profits for Newfield are expected to fall 21%.