Word meaning exercising the ability of your professional expertise

Solution 1:

You could choose integrity, defined in Mirriam-Webster as:

'firm adherence to a code of especially moral or artistic values'

Or probity, defined (again in Mirriam-Webster) as:

adherence to the highest principles and ideals

Either of those would imply that the newspaper should follow the ideals and standards of the industry. In the UK that would be the Editors' Code of Practice. The relevant part of the Code (section 1, on Accuracy) says:

  1. Accuracy

i) The Press must take care not to publish inaccurate, misleading or distorted information or images, including headlines not supported by the text.

ii) A significant inaccuracy, misleading statement or distortion must be corrected, promptly and with due prominence, and — where appropriate — an apology published. In cases involving IPSO, due prominence should be as required by the regulator.

iii) A fair opportunity to reply to significant inaccuracies should be given, when reasonably called for.

iv) The Press, while free to editorialise and campaign, must distinguish clearly between comment, conjecture and fact.

v) A publication must report fairly and accurately the outcome of an action for defamation to which it has been a party, unless an agreed settlement states otherwise, or an agreed statement is published.

Your sample sentence would then be:

In the era of fake news and post-truth, the newspaper would do well to exercise some journalistic probity and make it clear what the truth about the matter is.

Solution 2:

The word professionalism is defined in the Oxford online dictionary as

The competence or skill expected of a professional.

This definition, as it includes the word expected, implies the commitment and dedication to actually do the job properly. It would be quite possible for a skilled decorator, for example, to paint a room poorly but that would be unprofessional; particularly if he was being paid to do it properly. Similarly journalists who do not make the effort to check their facts can be accused, with justification, of acting unprofessionally. "Professionalism" is quite suitable in your sentence.

Solution 3:

Acumen noun : The ability to make good judgements and take quick decisions. ‘she hides a shrewd business acumen

To me, it then shows the expertise and ability to do something rather quick (which, again, shows the expertise).

Plus you can use it with any other word like 'journalistic acumen', 'medical acumen'...etc