It devotes a great deal of time to legislative scrutiny. It leaves MPs to agree the principle and it then gets on with focusing on the detail. It is not necessarily high-profile work, but it makes a significant difference to law.

This week saw the former head of M15, Lady Manningham-Buller, say on the floor of the House of Lords that she could not support Government proposals to hold terror suspects without charge for up to 42 days.

Each year, 2,000 to 4,000 amendments are secured to Government Bills in the House of Lords. It has been estimated that, when it comes to the detail of legislation, the House of Lords has double the impact of the House of Commons.

It fulfils a number of other functions, not least raising issues outside the context of party debate and scrutinising Government and public policy – not just British public policy but also proposals for EU law.

The House thus matters. What it does can be, and is, influenced by its members. Some members carry great weight in the House and, on occasion, can carry the House with them. But what is it that makes an effective member of the Lords?

This year marks the 50th anniversary of the passage of the Life Peerages Act 1958, enabling members to sit for life and not pass on their titles. It enabled new blood to be brought into the House, and life peers now form the bulk of the membership.

The House Magazine, the journal of both Houses, is running a competition to find the most outstanding life peer of the past 50 years. Twelve peers have been nominated.

They include a reverend, three women (including one of the four original female life peers), a field marshal, and a former prime minister (Lord Home of the Hirsel). Three are still in the House: Lord Howe of Aberavon (Geoffrey Howe), Lord Ramsbotham (General David Ramsbotham) and Baroness Williams of Crosby (Shirley Williams). It is a distinguished list, but what is it that sets apart the really effective peers?

There are four attributes that effective peers have. The first is knowledge of procedure. The Lords is very different to the Commons in that it is a self-regulating chamber. One does not have to catch the Speaker's eye in order to speak. Authority rests with the chamber itself.

The procedures are such that a determined member can exploit a range of opportunities to speak as well as table amendments. All amendments put down to Bills are debated (unlike in the Commons). Procedural opportunities are thus significant.

Lord Ramsbotham has utilised them to effect: he has spoken in the House more than 60 times during the past year.

The second attribute is knowledge of the subject. The House is best characterised as a House of expertise and experience. It has members who are expert in a range of fields and many who have served in leading positions. They can speak with authority. The House listens to those who demonstrably know what they are speaking about.

This lessens the impact of party. If party policy is to do "A", and someone who is clearly an expert on the subject explains how and why "A" won't work, it is difficult, if not embarrassing, to then toe the party line.

The third attribute is having the respect of the House. Peers who treat the House with respect gain respect. You can be an expert, but you may not carry the House if you make it obvious you regard yourself as the only person in the world who knows what they are talking about. Never turning up except for the occasion when you wish to impart your wisdom does not go down well.

Some of the leading figures in their field are to be seen regularly in the House, listening to others and not just taking part in debates in their own field. Among current members, Geoffrey Howe is one of the most assiduous attenders. So, too, are several other members who have held high office.

The final and obvious attribute is that of being a good speaker. The House will listen to any peer who speaks with knowledge and sincerity, however badly the speech is delivered, but a capacity to speak well enhances the impact of one's words. Here the procedures can be a problem as well as a strength. Speeches are time limited. It makes for good debate, with no-one droning on at length.

Speeches have to be prepared in order to maximise impact within the limited time. Some peers do not master it and cannot cover all their points. Others identify the key points and stay within their time. The skill is being able to convey a clear argument within sometimes three or four minutes, or, at best, 15 minutes.

There is one other attribute worth mentioning. It is not necessarily essential but it certainly helps, and that is to have a sense of humour. A one-line quip can get a speech off to a good start or enliven a debate. As long as the humour is on tap and not on top, it can be a wonderful asset.

It can make a difference and it also says something about the House. MPs can raise the temperature in debate by making partisan points. Peers can reduce tension by telling a joke. The atmosphere in the Lords is very different to that of the Commons.

There are some very able, and some very eminent, people working away quietly in order to improve the quality of legislation and of public policy. Some may not be that well known outside the House, but what they do inside is significant – and worth commemorating.