Alan Greenspan, chosen this month by President Reagan to succeed Paul A. Volcker as chairman of the Federal Reserve Board, loves raw data. Like a chef making a steak tartare, he adds diverse ingredients, blends them thoroughly but gently and lets the flavor of the real world come through.

Ask Greenspan why, say, steel prices have gone up and you will likely get an answer so fact-filled that you wonder whether plant managers and sales executives throughout the industry are filing weekly reports to him. His capacity to absorb information is enormous, and his understanding of the myriad interconnections within the American economy is surpassed by few, if any, other economists.

In his case, this detailed knowledge of the economy also comes with a keen sense of practicability. As an adviser to U.S. presidents, government agencies and many businesses, Greenspan's analysis and advice are almost always bounded by his perception of what is economically or politically possible.

This combination has made him, according to an official who was in the Ford White House when Greenspan was chairman of the Council of Economic Advisers, "probably the best consultant the world has ever seen."

How will the world's best consultant do as chairman of the Fed? Obviously no one knows, but the standards of measurement are being trotted out, to be used after his confirmation later this summer.

Many financial analysts are waiting for Greenspan to demonstrate his independence from Reagan and the administration, presumably by taking a tough line against inflation. Even though he has occasionally served as an outside adviser to the administration, he has no close personal relationship with the president.

Other analysts want him to defend the dollar. Some more liberal members of Congress are anxious that he show compassion for the unemployed by easing monetary policy, or at least by not tightening it, so that the economy can continue to expand.

There are concerns whether Greenspan, who for years has headed his own consulting firm, Townsend-Greenspan & Co., will operate effectively as head of a large organization where key policies are set by committee and other officials want to make sure they control a piece of the action. Other analysts worry about his lack of experience in international monetary circles. How will he do in negotiations over debt problems in less developed countries, others ask.

Perhaps more to the point, will events give Greenspan an opportunity to demonstrate his own degree of effectiveness at the Fed? His own praise of Volcker's record is based on the fact that Volcker followed monetary policies that were not necessarily dictated by the flow of events, and as far as Greenspan is concerned, that were generally wise policies.

Fed Vice Chairman Manuel H. Johnson, an earlier Reagan appointee to the board, as are all the other Fed governors save Volcker, said last week that with the arrival of Greenspan, "I don't anticipate any major changes in monetary policy or big differences of opinion.

"That's not to say Paul Volcker won't be missed. When you have 30 years of institutional knowledge and you go, we will miss that."

Early last year, not long after Johnson and Gov. Wayne D. Angell joined the board, they and Gov. Martha Seger and former Vice Chairman Preston Martin joined to press for a cut in the Fed's discount rate over Volcker's objections. The vote was withdrawn before it was announced to give Volcker time to negotiate a coordinated cut in rates with West Germany and Japan.

Since then, there have been no such confrontations, and on several occasions Volcker led the way to further cuts in the discount rate, the interest rate the Fed charges on loans to financial institutions. Recently members of the Fed's top policymaking group, the Federal Open Market Committee, have disagreed to some extent over how much effort should be made to support the dollar on foreign exchange markets, a key policy variable this year.

But the disagreements on this score have not produced dissents from the policy directive issued by the FOMC. From what is known about Greenspan's views on this issue, it appears likely he does not have a substantially different position, either.

As a consultant, a frequent witness at congressional hearings and a participant in other forums, Greenspan has expressed his views on many economic issues over the years. A careful reading of many of those statements suggests that as Fed chairman his main goal will be to control inflation. This is the goal of most members of the FOMC.

At a White House press conference at which his appointment was announced, Greenspan declared, "During the 1970s there was increasing fear that inflation was destined to ratchet ever upward with ultimately disastrous effects and consequences to economic growth and employment. Under Paul's chairmanship, inflation has been effectively subdued. It will be up to those of us who follow him to be certain that those very hard-won gains are not lost. Assuring that will be one of my primary goals."

Greenspan has consistently made such comments over the years. When he was CEA chairman he cautioned that one had to be careful about pushing the U.S. economy too rapidly toward full employment because no one could be confident of knowing at what rate of unemployment inflationary pressures would begin to build. One would want to approach that unemployment rate slowly, he said, because the costs associated with going too far too fast were so much greater than those associated with going too slowly.

The civilian unemployment rate in May was 6.3 percent for the second month in a row. Many economists think that the rate below which wage increases and overall inflation would begin to accelerate sharply is between 5.5 percent and 6 percent.

So far there is no evidence that wage gains are going up more rapidly, but with the unemployment rate as low as it is, Greenspan will likely be very cautious about seeking strong economic growth that could drive it down quickly.

Over the longer-term, Greenspan told his clients last March, "Federal Reserve policy is expected to focus equally on the domestic economy and the state of the exchange markets. . . .Moreover, the current long-term outlook is based on an essentially neutral monetary policy stance. . . .The enormous expansion of liquidity during the last few years does pose a potential inflationary threat, but one that we anticipate will be contained by the absence of either capacity pressure or labor market tightness."

Reflecting on what has happened so far this year, Greenspan went on to say that the presumption about monetary policy neutrality "depends on the absence of sharp declines in the dollar exchange rate." Such a drop in April led to a surge in long-term U.S. interest rates and caused the Fed to tighten monetary policy slightly.

Earlier in the year, Greenspan had forecast a drop of about 10 percent in the trade-weighted value of the dollar between 1986 and 1987, most of which has now occurred. His long-term projections included a further 23 percent decline in the dollar over the next 10 years, with about a 5 percent drop between 1987 and 1988.

With that kind of forecast on the table, some analysts thought he was becoming more circumspect when, at the White House press conference and in a Wall Street Journal interview the next day, he said there was evidence that the dollar has bottomed out.

But the analysts are going to have to get used to reading differently the tea leaves of statements from Fed chairmen. Volcker has been a master at deflecting questions, or at giving hints or making oblique references when he wants to point analysts' thinking in a particular direction without making a flat statement on a subject.

Greenspan, on the other hand, is given to prolix comments whose sentences are hung like Christmas trees with dependent clauses. He can deflect an inquiry with a burst of precision that requires study to figure out.

It appears at the moment that he is really saying three things about the dollar:

First, it came down abruptly in April and May and now seems to have stabilized.

Second, it likely will continue to fall during the coming year but less sharply than markets currently anticipate based on the futures market.

Third, as markets realize that the decline is slower than they had expected, forward contracts for the dollar will rise. Those contracts are now priced consistent with the Japanese yen rising over the next 10 years from its current value of about 142 to the dollar to about 80. Such an exchange rate 10 years from now would mean over the intervening period that inflation in the United States will run about 5 percentage points a year higher than in Japan, or that the United States will end up with a very large surplus in its international transactions instead of today's huge deficit.

On April 20 on a Public Broadcasting System television program, Greenspan had this to say about the dollar:

"It is important . . . to remember that it is the rate of change of the dollar's exchange rate, not its levels, that affects the rate of price inflation and interest rates {in the United States}. If the adjustment to a lower exchange value of the dollar is dragged out, it is possible to reach a new balance without setting off a further disstabilizing run-up in either interest rates or consumer prices.

"A sharply falling dollar, however, would, by pushing interest rates markedly higher, tilt the economy downward, accelerating inflation and perhaps even altering the ultimate equilibrium value of the dollar.

"Economic policymakers both in the United States and elsewhere are, accordingly, in a very difficult position. If they announce a goal of gradual dollar devaluation, the market will produce that level immediately, with all its adverse consequences. If they announce that the current level is the right one, they are going to have a tough time enforcing it," he said.

In another contentious area, banking regulation, Greenspan is widely expected to favor less government intervention than Volcker has. Certainly Greenspan believes in the efficacy of market forces as a regulator of economic activity. When he was in the Ford administration, for instance, he routinely excused himself from discussions of antitrust enforcement because he philosophically was opposed to the concept of antitrust legislation.

However, there are signs his views have been tempered in recent years, and his pragmatism will limit his taking extreme positions. The need to operate effectively at the Fed, where consensus-building is the usual approach, will also impose limits.

And one should be cautious in predicting which way Greenspan might come down on a particular issue. For instance, at the White House press conference, he said, "I'm always fearful of markets and very respectful of them, and intend to watch markets as closely as I always have." On occasion that respect for the way markets behave could indicate a need for more regulation rather than less.

For instance, in recent years there have been many advocates of the prompt release of the policy record of decisions by the Federal Open Market Committee regarding monetary policy. Volcker, like his predecessors, resisted and Greenspan may, too. In an interview a few weeks before being named to the Fed, Greenspan said that not releasing the policy record quickly adds to uncertainty among market analysts, with traders backing their differing views of Fed intentions by taking different positions in the market.