Some approaches subsume science diplomacy under public diplomacy. In this sense, science diplomacy is about winning hearts and minds; it is about creating a positive image of one’s country.
For clarity, let us look at a definition of public diplomacy. According to the USC Center on Public Diplomacy (CPD), it is defined as ‘the transparent means by which a sovereign country communicates with publics in other countries aimed at informing and influencing audiences overseas for the purpose of promoting the national interest and advancing its foreign policy goals. [...] The concept of soft power coined by international relations scholar Joseph Nye has, for many, become a core concept in public diplomacy studies. Nye defines soft power as "the ability to get what you want through attraction rather than coercion or payments"'.
From this description and the examples on this page, we can see that science diplomacy is much more than public diplomacy and the one should not be reduced to the other. Having said this, it is important to recognise that for many countries, and in particular the USA, the practice of science diplomacy often has strong elements of public diplomacy.