To find the pattern of the sequence, we begin by converting each of the decimal values into a common fraction. The first term $ 0 $ is equal to $ \frac{0}{1} $. The next term, $ 0.5 $, can be written as $ \frac{5}{10}=\frac{1}{2} $. To express $ 0.\overline{6} $ as a common fraction, we call it $ x $ and subtract it from $ 10x $: $$\begin{array}{r r c r@{}l} &10x &=& 6&.66666\ldots \\ - &x &=& 0&.66666\ldots \\ \hline &9x &=& 6 & \end{array}$$ This shows that $ 0.\overline{6} = \frac{6}{9} = \frac{2}{3} $. The fourth term in the series, $ 0.75 $, becomes $ \frac{75}{100}=\frac{3}{4} $. Thus, when we write fractions instead of decimals, our sequence is: $$\frac{0}{1}, \frac{1}{2}, \frac{2}{3}, \frac{3}{4}, \cdots$$ By observing this sequence, we realize that the first term of the sequence is $ \frac{0}{1} $ and each successive term is found by adding $ 1 $ to both the numerator and denominator of the previous term. Thus, the next term in the sequence is $ \frac{3+1}{4+1}=\frac{4}{5}=\boxed{0.8} $.