The article is very fair, showing that an investment in the company's shares at the beginning of 1996 would have seen them only marginally outperform the index over a period of 3 years. There's no arguing with the facts. A look at the company's growth in book value per share from 1995 to 1997 highlights the vagaries of the stock market over the shorter term. For any company, that is an excellent performance. However, this appreciation obviously wasn't reflected in the company's share price.
Book value is a relatively simple concept.
Firstly, forget a company is quoted on the stock exchange, because market value has no bearing on book value. Say you are starting a company and you issue 100,000 shares at 100p each. This gives the company a book value of 100,000 and a book value per share of 100p. Five years down the track, you've struggled by, managing to make a total net profit of 50,000. From this surplus, you pay yourself a total of 20,000 in dividends, leaving 30,000 to be invested back in the business.