TWO AND A HALF MONTHS into its term of office, we have heard a lot about the Carter administration's views on certain issues - strategic arms, human rights, economic stimulus and political symbolism - but very little on another: social welfare. The action has been elsewhere and will probably stay elsewhere until the President's promised welfare reform is drawn up. But the administration did take three separate actions this week that tell you something about its approach to social welfare issues - and we think the cumulative message is good.

There is, first, Mr. Carter's proposed revision of the food stamp law. It is meant to stay within the rough limits of current expenditures. What it would do within those limits is to make the program more accessible to the extremely poor - those believed to be unable to afford to participate in the program now - and less accessible to some of its better-off beneficiaries. Since, despite the mythology to the contrary, we are not dealing at the upper end of the income scale with vast hordes of Maserati-driving, polo-playing cheaters, there will in fact be some loss of benefits by people who could hardly be described as very well-off.

Still, with only a fixed amount to spend, the administration, in our judgment, made the right choice; and it also was right not to seek to enlarge the program substantially since the food stamp program in the next couple of years is likely to be incorporated into whatever larger welfare reform the administration comes up with. What it has recommended is bound nonetheless to be controversial, especially its proposal to eliminate that feature of the law which now requires the poor to set aside a fixed amount of their income to spend on food in order to get the "bonus" of stamps. But eliminating this feature would likely reduce middleman graft and enable some of the poorest of the poor to participate for the first time. It is going to be rough for the Carter proposal in Congress, But we think the administration is on the right track.

The second event worth noting is the protests of hundreds of disabled persons at HEW against Secretary Califano's refusal to sign a pack of regulations drawn up in the last administration and intended to elaborate on a 4-year-old statue prohibiting discrimination against the handicapped in any program receiving federal aid. Mr. Califano was absolutely right to refuse to sign these regulations and so was his predecessor, David Mathews, who also refused to sign them.

These are terrible regulations - confusing, prolix, complicated fuzzy and bound to do far less for the disabled citizen seeking fair play than for the lawyer seeking a guaranteed annaul income. As an example: Under the regulations and interpretation that two secretaries have refused to sign, it isn't clear that employers might not end up with some obligation to hire drug addicts. Mr. Califano has pledged to draw up new rules within a couple of months. We think the protesters should give him the chance: They are fighting for the right principle but the wrong set of regulations.

Finally, there is the administration's decision to move in a big way into the field of immunization against preventable childhood diseases. The immunization figures are bleak. The need is plain, and this is an area in which the federal government has the resources to move effectively. The cost is likely to be repaid many times over in the materially improved health (and subsequently lessened medical costs) of the children who receive these immunizations.

In responding to requests for help in the immunization program from private organizations, the administration has shown that the federal government does have the capacity to act quickly, wisely and imaginatively to meet a clear social need. In refusing to sign the set of regulations concerning the law on disabled persons' rights, it has shown it is willing to take political heat, if necessary, to get the right thing done. And in its food stamp proposals, it has shown that it is willing to make tough choices and that it can make them well. That is why we think the news on the social welfare front is good.