I also fail to see why the contractor, EDPS Systems, asked for 'simulated data'.

There is little possibility of tainting original data (with a properly written program, anyway), and there were only a few thousand records.

Actual data could, and should, have been used. For one thing, simulated data rarely gives you the range of variations of the real thing. Also, it takes time and knowledge of the original database to create 'simulated data', and who has that?

Given what is known about this incident, it appears EDPS Systems is an inexperienced agent which hardly knows what's going on.

Which brings us to the question: why was it hired by the Independent Police Complaints Council in the first place?

FELIX LUK, Ho Man Tin

Comparisons mislead

I wish to set the record straight on the article 'Developers cashing in on eco-buildings' (March 13).

The article compared the premiums paid for the green features in four private residential developments with the estimated value of the green features both at the time of sale and currently. This is misleading, and we must point out the following:

Under regulations issued jointly by the Building, Lands and Planning departments, payment of premiums is required for green features built for the exclusive possession and enjoyment of owners and residents of units - that is, balconies, utility platforms and non-structural prefabricated external walls.

Green features that serve all owners and residents of the development - such as wider common corridors, bigger lift lobbies, communal sky gardens and mail delivery rooms, with mail boxes - do not attract the payment of a premium;

Not all the green features form part of the individual units for sale, and hence it is incorrect to assess the value of the green features by applying the estimated selling price per square foot to the total exempted floor area of all green features; and

The premium payable was assessed on the land value. The estimated values of green features quoted in the article were based on the estimated selling prices of completed units, which included construction and other development costs. The two figures were derived from completely different bases and assessed at different points in time. Therefore, they cannot be compared directly.

We trust the above has clarified the position. As the policy has been implemented for some time, relevant departments are reviewing its effectiveness in encouraging the design and construction of green buildings.

ROBIN IP MAN-FAI, deputy secretary for Housing, Planning and Lands

Stop ruining my school

As a student at an English Schools Foundation school I am appalled by the ESF management. The problem is with them, not with the schools, so why are hard-working staff and parents suffering?

What made ESF schools distinctive and special was the school community. Staff and students joked together, supported each other, and made every event memorable. But pay cuts have undermined the morale of the staff, although they have tried to hide this from the students. They no longer have the same camaraderie with the students; instead they hide in the staff room and refuse to attend major school events.

We don't blame them. With the introduction of International Baccalaureate courses, they are sometimes forced to work at weekends without any compensation. They are just victims in the shortcomings of the ESF.

The students are also dissatisfied, anti-school talk is spreading and truancy is increasing. Now, with the increase in school fees, students will hear more complaints at home.

A common misconception is that all children who attend ESF schools are from rich families, but the reality is that many of these families struggle to get by and many students may be forced to drop out.

All is not well in ESF-land and I think the management has much to answer for. The ESF aims to educate students in the best environment possible. Instead, politics have made that environment substandard. I ask the ESF to stop punishing innocent staff, students and parents, and to keep the politics out of my education.

NAME AND ADDRESS SUPPLIED

Plant more trees

I live across the border in Shenzhen, where the air quality seems much better than in Hong Kong. A contributing factor may be that there are more parks full of trees.

Hong Kong should plant more trees in areas like Causeway Bay, Wan Chai and Central, and Hongkongers should stop blaming the mainland for poor air.

ADAM LEE, Shenzhen