No. Strength is determined by the ratio of coffee to water, grind size to contact time and water temperature. Coffee extracts faster at higher temperatures and smaller grind sizes. A light roast does not mean you will have a weak flavoured coffee, nor does a dark roast mean you will have a strong flavoured coffee. A light roasting profile will be used to preserve the natural fruity, sweetness and acidity characteristics of a bean. A medium roasting profile will be used preserve the natural nutty, chocolatey and mild acidity characteristics of a bean.