WHAT do people mean when they say the words "good school"?

You hear this phrase frequently, particularly around the time of year the league table results appear, showing the percentage of pupils leaving school with a brace of Highers.

This year, for Scotland, the usual suspects were at the top of the chart: Jordanhill School, in Glasgow; St Ninian's Secondary and Williamwood High, both in East Renfrewshire.

For the "top performing" five schools in Scotland, only one, St Ninian's, has leavers from the most deprived backgrounds - six per cent.

Glasgow Gaelic School comes sixth in the league table and has 23 per cent of pupils from the most deprived postcodes. The measure of deprivation used for the league tables comes from the Scottish Index of Multiple Deprivation (SIMD) with the most deprived being one, so SIMD 1.

The Gaelic School has small enough numbers of school leavers that a few pupils can skew its results. This year it had 23 per cent of school leavers from SIMD 1 but last year it had none.

For the rest of the top 10, Bishopbriggs Academy had nine per cent while Douglas and Bearsden Academies had four per cent. The others also had none.

Let's look at Glasgow. Drumchapel High School has 93 per cent of pupils coming from the most deprived postcodes in Scotland. Springburn Academy has 91 per cent. Lochend Community High has 90 percent. Those are some stunning numbers.

The problem with league tables is that they tell you almost nothing about a school's ethos or how it supports pupils to improve.

Each year at league table time, the "high performing" local authorities put out statements about their successes. When an East Renfrewshire head teacher or East Dunbartonshire Council senior official comes out boasting about their schools' success I cringe.

Surely they must feel a little sheepish too? Deprivation has a forceful effect on exam attainment.

The schools at the top of the chart have pupils from almost exclusively affluent backgrounds. They have parents ready and willing to pay huge property premiums to get their children into the "right schools", which means parents are literally and figuratively invested in their child's attainment.

Their pupils go home at night and have adequate space to study. They have laptops and iPads. They perhaps have a private tutor.

Their pupils are not coming to school hungry or inadequately clothed. They haven't been up at the crack of dawn to feed and prepare younger siblings for school because their parents are not caring for them. They are given the best and told they deserve it.

I interviewed a school head teacher last year who told me she will drive families in need to foodbanks. She will go to the Jobcentre with parents struggling to understand the benefits system. She organises a clothing bank for pupils. She goes out to homes to find out why pupils aren't at nursery.

So there you have her: social worker, benefits advisor, councillor and a headteacher to boot.

That's not for a minute to say that middle class teenagers don't work hard for their exam successes. Of course they do.

It's similarly not to say that poverty is an excuse and Glasgow schools are very clear to make that distinction. It is not an excuse, it is a fact.

But pitting Williamwood High School against nearby Castlemilk High School is like arranging a badminton match where one competitor is given a racket and the other is given a fish.

A young teenager told me recently that East Renfrewshire is a good place to live because "we have the top two best performing schools." I don't know about you, but when I was 13 I was not spending my dinner break discussing the placement on the league tables of my high school.

I wonder how that comes to permeate a 13-year-old's consciousness, in between noticing girls and playing the XBox? Are his parents telling him that he goes to a top performing school? Does it come from the school itself?

Whatever the source, it's an unhealthy attitude for a young head. Eventually they will be out in the world mixing with all sorts of people. To foster the idea of "us" and "them" does no good for either party.

For certain parents the words "good school" mean "a school where my child will mix with other middle class children." It's quite extraordinary that this is a point of pride and not embarrassment.

If East Dunbartonshire and East Renfrewshire boast the "good schools", it follows that Glasgow's secondaries are the "bad schools", which is plainly nonsense.

There is tremendous work being done in our schools, of which the city should be proud. The phrase "good school" needs new meaning. A "good school" is currently one where children who are likely to succeed do succeed.

How about we talk about "good schools" as those supporting our most vulnerable pupils towards success? They are the ones really deserving of support and praise.