NOT LEAST among Mikhail Gorbachev's accomplishments is that he has killed Kremlinology, the strange science that sought to understand Soviet policy by piecing together a jigsaw of facts and hints about the Soviet leadership. Kremlinology, which thrived in a vacuum of real information, became increasingly irrelevant with the shift to greater openness.

In its classic form, Kremlinology had two essential ingredients: It treated the top Soviet leadership as a Byzantine court in which policy making was confined to a small and identifiable number of key party members and bureaucrats; and it tried to circumvent the secrecy surrounding the Soviet leadership by unearthing every scrap of information about these men, often in office for 40 years or more, to form a picture of how the Soviet political establishment thought, worked and acted.

These were not unreasonable approaches under Stalin and his successors -- when the Kremlin tried to run Soviet society like an army. But by the end of 1986, both the secrecy and the semi-military system of command were dissolving. Today, the main theme of Soviet politics is the struggle between conservatives and radicals within the party. And it is beginning to be possible to learn more about it from reading the Soviet press than puzzling over the lineup on top of Lenin's tomb.

These changes in Soviet society have produced a highly casualty rate in the reputations of Kremlinologists. Few of them could reprint their comments of even three years ago without a wince of embarassment. In 1983, for instance, Lt. Gen. William Odom, now head of the National Security Agency and one of the Pentagon's leading experts on the Soviet Union, had two predictions for the post-Brezhnev era: At home, "sound and fury about domestic reform accompanied by little actual change," while in foreign policy, "we can expect threats to end detente."

The model for bad Kremlinology may have been an official in the British Foreign Office of 1917. Worried that the Bolshevik Revolution would lead Russia to sign a separate peace treaty with Germany, he suggested to his superiors a novel plan. He said that during his many years of dealing with Russians, he had noted their fondness for decorations. He therefore proposed that Britain award Lenin a knighthood and Trotsky some lesser but still worthwhile honor to encourage them to break off talks with Germany.

The scheme to make Lenin "Sir Vladimir" was stillborn, since the Russians and Germans went ahead and signed a peace agreement. Yet the approach -- and the assumption that nothing ever really changes in Russia -- has remained extraordinarily potent. It is all the more dangerous because 95 percent of the time it is correct about the Soviet Union or anywhere else in the world. The problem is that 5 percent of the time, it is fatally wrong.

Not that there were many outward signs of this in the early 1980s as western academics, diplomats and journalists tried to work out the shape of the new Soviet leadership. Secrecy had reached absurd levels. In 1984, as I prepared to leave London for Moscow to replace an expelled colleague as correspondent for the Financial Times, a Soviet journalist warned me: "Remember, no Soviet official ever lost his job because he refused to talk to a western correspondent." This turned out to be all too true. A month after I arrived, Marshal Dmitri Ustinov, the defense minister and one of the most powerful men in the country, died -- but the first we journalists in Moscow learned about it was from an old lady mopping the floor of the hall where the world chess championship was taking place. Two journalists who had gone to watch the chess discovered from a notice on the door that it was cancelled. When they asked the cleaning woman why, she explained that it was because the hall was needed for the lying-in-state of Ustinov, who had died the previous night.

Several journalists, worried by the lowly status of their source, attributed the information to a "Soviet official," as in a sense she was.

To understand Western coverage of the Soviet Union in those pre-glasnost years, it may help to know how we correspondents lived. The Soviets insisted that all foreigners, including East Europeans and other Soviet allies, live in some 20 foreigner-only blocks guarded by 24-hour-a-day police guards. This gave our expatriate lifestyle a peculiarly colonial flavor, like living in a British rubber plantation in Malaya in the 1920s. Diplomats, far more numerous than the 400 or so journalists, dictated the tone of social life by giving dinner parties, often of extraordinary tedium, as a form of professional ritual.

In building a barrier between foreigners and ordinary Soviets, the authorities created a siege mentality in the foreign community -- which mirrored the siege mentality of Soviets themselves. "Remember, we are just as paranoid as you," one Soviet diplomat told me. Up to 1985 the government still treated foreign journalists more as a security question than a public-relations problem.

Mass terror had ended on Stalin's death but Soviet society in 1984 still had the smell of a barracks run by aging sergeant majors who saw any form of dissent as at best indiscipline and at worst potential treachery. The peculiar living conditions and consequent sense of embattlement of a foreign journalist or diplomat meant that he was peculiarly ill-placed to regard as significant any changes away from this model. Even so, the worst that could probably happen to a journalist was expulsion, probably in reciprocity for the expulsion of Soviet journalists, but this fear was real enough. In 1985, the dozen or so resident British correspondents were summoned to the British embassy, housed in some splendor across the river from Kremlin in the palace of a pre-revolutionary sugar millionaire, to be told that half us were being expelled.

I drove away from the embassy with Robin Gedye, the newly arrived Daily Telegraph correspondent, who complained sadly: "After three weeks in Moscow devoted to putting together the furniture, laying linoleum in the kitchen and trying to exterminate the cockroaches, I find myself suddenly expelled for impermissible activities."

Glasnost brought its own problems. Academic, diplomatic and journalistic visitors who started to pour into Moscow soon after Mikhail Gorbachev was elected general secretary in 1985 were ill-equipped to assess the health of glasnost and perestroika. Despite greater Soviet willingness to talk, the lack of visible material change meant that visitors always worried that they were being hoodwinked. They wanted something more tangible as material evidence that things were on the move.

To anyone living in Moscow, it gradually became evident that the perceptions of visitors were conditioned less by the interviews they conducted than by the quality of the hotels in which they stayed. In the absence of concrete information, visitors regarded the particular virtues or failings of their hotel as a symbol of the condition of Soviet society as a whole. Hence those with rooms in the relatively comfortable National were generally optimistic about the changing face of the Soviet Union. Others, resident in the modern but overlarge Cosmos hotel far from the center of town, were more neutral.

Unfortunately for the Soviets, there are a great many more bad hotels than good ones in Moscow. And in these, the rooms smell, the service is non-existent and the food inedible. Visitors staying in the vast barracks-like Rossia hotel, with rooms for 4,000, returned home to report that perestroika was a sham. The Beograd, opposite the Soviet Foreign Ministry, is if anything worse. Nobody could stay there for long and still have positive thoughts about the Soviet state and people.

The Hungarians have handled this better. Early on in their economic reforms after 1968 they built four or five luxury hotels on the banks of the Danube in central Budapest. The plan was to develop the tourist trade but the effect was that any journalist or visiting academic, come to view Hungary's experiment with market socialism, was staying in a hotel of West European standards of comfort. The result was that despite a fall in real earnings in Hungary over the past decade, reports on the progress of the country's timid economic reforms have remained almost invariably upbeat.

Wherever they stayed in Moscow, most visitors ended up by making a serious mistake. It is not so much that they exaggerated the difficulties facing the Soviet Union -- offices filled with ossified bureaucrats and factories with obsolescent machinery -- but they almost invariably underestimated the range of options available to a vast and powerful country.

The old Kremlinology also helped mislead the West by implying that a small group of men at the top wholly determined policy, and that the fundamentals of Soviet society could never change. Neither assumption had ever been wholly correct. What made the Soviet Union tick was always a lot more complicated than what went on in the Politburo or the Central Committee. Under Brezhnev the Soviet leadership might be moribund but Russian society changed enormously as people surged into the cities and acquired secondary and higher education. These were vast changes in the lives millions of people.

There were other, more respectable reasons for foreigners to be wrong about events in Moscow. Our non-official sources of information tended to be members of the Soviet intelligentsia, and most of them were skeptical at first about Gorbachev -- predicting that he would offer "Brezhnevism without Brezhnev." By the end of 1986, Soviet intellectuals had shifted strongly towards Gorbachev. But in both phases -- skeptical and enthusiastic -- their lack of political experience made them prone to hysteria and poor judges of the political situation. For journalists and diplomats, day-to-day events in the Soviet Union became easier to report from the second half of 1986. Despite the arrest of Nick Daniloff at the end of August, Soviet officials, intellectuals and ordinary citizens became much more willing to talk to foreigners of any description.

Increased access made it both more interesting and more laborious for journalists or diplomats to write about the Soviet Union. It became less and less reasonable for a correspondent to quote opinions and views ascribed to "a western diplomat," a phrase previously justified because of lack of other sources that had, since diplomats had no better sources of information than journalists, the disadvantage of giving a spurious authority to speculation.

By early 1987 it was beginning to become possible to report Soviet politics much like anywhere else. Even surviving Kremlinologists had to admit that for a political system that was not meant to change, the Soviet Union was behaving very strangely.

The widely varying analyses of what is going on in the Soviet Union today -- whether Gorbachev is in trouble or in firm control -- reflect, in part, a disagreement between those who reject old-style Kremlinology and those who, often unconsciously, continue to practice it. Traditional Kremlinology interpreted any sign of a public difference of opinion in the Politburo as being like a split in the general staff of an army. It meant a major factional dispute. Today it is very doubtful that every disagreement between Gorbachev and Ligachev (normally classed as a conservative rival) means that two factions are colliding. If we assume a greater diversity of opinion within the Soviet leadership, then such divisions are still serious but in the long run far less ominous for Gorbachev.

In other words, should we look at Gorbachev today as being more like Nikita Khrushchev in 1964 or President Roosevelt in 1934? If the first, then Gorbachev is in trouble; if the second, then the presence of vocal conservatives in the administration means far less.

Over the last year, the great fortress built by Lenin and Stalin, long in bad repair, was visibly dissolving. The very messiness of the process, which so disturbed visitors to Moscow, should have been reassuring because it showed that reform was a response to real needs and not just a little plan devised in, and therefore reversible by, the Politburo.

Kremlinology, which had sought to explain how the Soviet state machine worked, was also in decline as an influence on western public perception of what was happening in Moscow. It had always had a dubious reputation but, after 1985, Kremlinologists had explained too little of what was going on in the Soviet Union to retain much credibility. Their books and articles, published only a few years before, already had an out-of-date feel, like rereading the vacuous speeches of Leonid Brezhnev and other Soviet leaders whose actions they had long sought to explain.

Patrick Cockburn, on leave from The London Financial Times, is a senior associate of the Carnegie Endowment for International Peace.